JAMB UTME - Mathematics - 2015

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A regular polygon is a polygon with equal sides and equal angles. The formula to find the interior angles of a regular polygon is: Interior Angle = (n - 2) x 180 / n where n is the number of sides of the polygon. We are given that the interior angles of the regular polygon are 120°. Substituting this value into the formula, we get: 120 = (n - 2) x 180 / n Simplifying this equation, we get: 120n = 180n - 360 360 = 60n n = 6 Therefore, the regular polygon has 6 sides.

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The trinomial = $a^2-4a+4$
$a^2-b^2-4a+4=(a^2-4a+4)-b^2$
$(a^2-2a-2a+4)-b^2$
$a(a-2)-2(a-2)-b^2$
$(a-2{)}^2-b^2$
$(a-2+b)(a-2-b)$

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P(A outcome) = $\frac{1}{6}$, P(B outcome) = ¼
P(A ∪ B) = 1/12, P(A ∩ B)
P(A ∩ B) = P(A) + P(B) − P(A ∪ B)
1/6 + 1/4 − 1/12
= (2 + 3 − 1) ÷ 12
= 4/12
= 1/3
P(A ∩ B) = 1/3

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6½ − 2¾ + 1½
73/12 − 11/4 + 3/2
[(73 − 33 + 18) ÷ (12)]
58/12
29/6
$4\frac{5}{6}$

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The formula for finding the simple interest on a principal amount P for a period of t years at an interest rate of r per annum is:

simple interest = P * r * t / 100

In this case, P = 325, t = 5, and r = 3, so we can plug in the values into the formula:

simple interest = 325 * 3 * 5 / 100
simple interest = 48.75

So, the simple interest on ₦325 in 5 years at 3% per annum is ₦48.75.

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[1 ÷ (x+1)] + [1 ÷ (x − 1)]
= ((x − 1) + [(x + 1)) ÷ (x+1)(x − 1)]
Using the L.C.M.
= (x − 1 + x + 1) ÷ (x + 1)(x − 1)
= (x + 2 − 1 + 1) ÷ (x + 1)(x − 1)
= 2x ÷ (x + 1)(x − 1) =2x ÷ (x + 1)(x − 1)

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(0.09)2 = 0.09 × 0.09
= 0.0081
= 0.008100 to 4 significant figures
Please, start counting first from the non-zero digits i.e. 8

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The answer is {1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 15}. (A ∪ B) means the union of sets A and B, which is the set of all elements that are in either set A or set B or both. Therefore, (A ∪ B) is {1, 3, 5, 7, 9, 12, 15}. Then, we take the union of (A ∪ B) and set C, which is the set of all elements that are in either (A ∪ B) or set C or both. Therefore, the final answer is {1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 15}. This is because all the elements in A, B, and C are present in the final set.

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The formula for the volume of a cylinder is V = πr^2h, where "r" is the radius of the base, "h" is the height, and π (pi) is a mathematical constant approximately equal to 3.14. In this case, the height of the cylinder is 4cm, and the radius is 5cm. So we can substitute these values into the formula to find the volume: V = πr^2h V = π(5cm)^2(4cm) V = π(25cm^2)(4cm) V = π(100cm^3) V = 100π cm^3 Therefore, the volume of the cylinder is 100π cubic centimeters. We can leave the answer in terms of π or use the approximate value of 3.14 to get an estimate: V ≈ 100(3.14) cm^3 V ≈ 314 cm^3 So the answer is option C: 314cm^2.

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To solve for x in the equation √(2x + 2) − √x = 1, we can use algebraic manipulation to isolate x on one side of the equation. Here's how: 1. Start by adding √x to both sides of the equation: √(2x + 2) = √x + 1 2. Square both sides of the equation to eliminate the square root: (√(2x + 2))^2 = (√x + 1)^2 Simplifying the left side: 2x + 2 = x + 1 + 2√x + 1 3. Rearrange terms: x - 2√x + 1 = 0 4. Factor the left side of the equation: (√x - 1)^2 = 0 5. Solve for x by taking the square root of both sides: √x - 1 = 0 √x = 1 x = 1^2 = 1 Therefore, the solution to the equation √(2x + 2) − √x = 1 is x = 1.

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$[1÷(x^2+3x+2\left)\right]+[1÷(x^2+5x+6\left)\right]$
= $1÷(x^2+3x+2)+[1÷(x^2+5x+6\left)\right]$
= $[1÷((x^2+x)+(2x+2)\left)\right]+[1÷((x^2+3x)+(2x+6)\left)\right]$
= [1 ÷ (x(x + 2) + 2(x +1))] + [1 ÷ (x(x + 3) +2(x + 3) )]
= [1 ÷ (x + 1)(x + 2)] + [1 ÷ ((x + 3) + (x + 2))]
=((x + 3) + (x + 1)) ÷ (x + 1)(x + 2)(x + 3)
Using the L.C.M
=((x + x + 3 + 1)) ÷ (x + 1)(x + 2)(x + 3)
=(2x+4)/(x+1)(x+2)(x+3) =2(x+2)/(x+1)(x+2)(x+3)
= $\frac{2}{(x+1)(x+3)}$

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log101.5 + 3 log102 − log100.3
log101.5 + log1023 − log100.3
[log10(1.5 × 23) ÷ log100.3]
[log10(15/10 × 8 ) ÷ log10( 3/10)]
log10(15/10 × 8 × 10/3 )
log1040

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Area of a circle (A) = πr2
Radius = 4cm
π = 3.142
A = 3.142 × (4)2
= 3.142 × 16
= 50.272
A = 50.3cm2 (1dp)

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dy/dx $(4x^3+3x^2+2x+1)$
= $12x^2+6x+2$
⇒ $12x^2+6+2$
Divide both sides by 2
$\frac{12x^2}{2}-\frac{6x}{2}-\frac{2}{2}$
= $6x^2+3x+1$
dy/dx
= $6x^2+3x+1$

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To rationalize the expression 5 ÷ (2 − √3), we need to eliminate the square root in the denominator. We can do this by multiplying both the numerator and denominator by the conjugate of the denominator, which is 2 + √3. This is because when we multiply the conjugate of the denominator by the original denominator, we get a difference of squares that simplifies the expression: 5 ÷ (2 − √3) * (2 + √3) / (2 + √3) Simplifying the numerator by multiplying the terms inside the brackets, we get: 5(2 + √3) / (2^2 - (√3)^2) Simplifying further, we get: 5(2 + √3) / (4 - 3) 5(2 + √3) / 1 Therefore, the rationalized form of the expression is 5(2 + √3), which is equivalent to option C.

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To determine how much the second staff receives, we need to find out the total ratio of the ages of the three staff, which is 18 + 20 + 22 = 60. Next, we need to find the ratio of the second staff's age to the total age, which is 20/60 = 1/3. Then, we multiply the ratio by the total amount collected to find how much the second staff receives. So, 1/3 x ₦120,000 = ₦40,000. Therefore, the second staff receives ₦40,000. Answer (c) is correct.

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The expression x^2 - 2x - 15 can be factored into the product of two binomials. To find these binomials, we can use the "ac method," where we try to find two numbers that multiply to -15 and add up to -2. These numbers are -5 and 3. We can then write the expression as:

(x - 5)(x + 3)

So, the expression x^2 - 2x - 15 can be factored as (x - 5)(x + 3).

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The power set of a set is the set of all possible subsets of that set, including the empty set and the set itself. The formula for finding the power set of a set is 2^n, where n is the number of elements in the original set. In this case, Z has four elements, so the number of subsets is 2^4 = 16. Therefore, the power set of Z has 16 elements, which is the answer.

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To simplify the expression 2.04 × 3.7, we can use the distributive property of multiplication over addition. That is: 2.04 × 3.7 = (2 + 0.04) × 3.7 We can now expand this expression as: (2 + 0.04) × 3.7 = 2 × 3.7 + 0.04 × 3.7 Simplifying further: 2 × 3.7 = 7.4 0.04 × 3.7 = 0.148 So, substituting these values back into the expression: 2.04 × 3.7 = 7.4 + 0.148 = 7.548 Rounding this answer to two decimal places, we get: 2.04 × 3.7 = 7.55 Therefore, the answer is option D - 7.55.

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The formula for the volume of a cone is given by: V = (1/3)πr²h where V is the volume, r is the radius of the base of the cone, h is the height of the cone, and π is a constant value of approximately 3.14. Substituting the given values into the formula, we have: V = (1/3)π(5cm)²(6cm) Simplifying this expression, we get: V = (1/3)π(25cm²)(6cm) V = (1/3)π(150cm³) V = 50π cm³ Using a calculator to approximate π to two decimal places (π ≈ 3.14), we have: V ≈ 157 cm³ Therefore, the correct option is: 157cm3

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To solve the problem, we need to use the concept of proportionality. We can set up a proportion between the return and the investment amount: Return/Investment = X/₦450,000 We can rearrange this to solve for X: X = (Return * ₦450,000) / Investment Now, we can use this equation to find the return Y on an investment of ₦700,000: Y = (X * ₦700,000) / ₦450,000 Substituting the given values, we get: X = (₦25,000 * ₦450,000) / ₦450,000 = ₦25,000 Y = (₦25,000 * ₦700,000) / ₦450,000 = ₦38,888.89 (rounded to ₦38,888.90K) Therefore, the answer is option D: ₦38,888.90K.

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1st G.P. = a =2
2nd G.P. = ar − 1 = 54
2(r) = 54
r = 54/2 = 27
r = 27
3rd term = ar2 = (2) (27)2
2 × 27 × 27
= 1458

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√30 × √40
= √(30 × 40)
= √(3 × 10 × 4 × 10)
= √(400 × 3)
= √400 × √3
= 20 × √3
= 20√3

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The formula for finding the number of elements in the union of two sets X and Y is:

n(X U Y) = nX + nY - n(X ∩ Y)

where nX is the number of elements in set X, nY is the number of elements in set Y, and n(X ∩ Y) is the number of elements in the intersection of X and Y. In this case, nX = 15, nY = 12, and n(X ∩ Y) = 7, so we can plug in the values into the formula:

n(X U Y) = 15 + 12 - 7
n(X U Y) = 20

So, the number of elements in the union of X and Y is 20.

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$[1÷{64}^{(x+2)}]=[4^{(x-3)}÷{16}^x]$
${64}^{-(x+2)}=\left[4^{(x-3)}\right]÷\left[{16}^x\right]$
Break down 4, 16 and 64 into smaller index numbers:
$2^{-6(x+2)}=2^{2(x-3)}÷2^{4\left(x\right)}$
$2^{-6x-12}=2^{2x-4x-6}$
$2^{-6x-12}=2^{-2x-6}$
− 6x − 12 = − 2x − 6
Collect the like terms:
−6x + 2x = −6 + 12
−4x =6
x = $\frac{6}{4}$
x = $\frac{-3}{2}$

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To find the curved surface area of a cone, we need to use the formula: `Curved Surface Area = πrs` where `r` is the radius of the base of the cone and `s` is the slant height of the cone. To find the slant height of the cone, we can use the Pythagorean theorem, which tells us that: `h^2 + r^2 = s^2` where `h` is the height of the cone. Substituting `r = 3cm` and `h = 4cm`, we get: `4^2 + 3^2 = s^2` `16 + 9 = s^2` `25 = s^2` `sqrt(25) = s` `s = 5cm` Now, substituting `r = 3cm` and `s = 5cm` into the formula for curved surface area, we get: `Curved Surface Area = πrs` `= 3.14 × 3 × 5` `= 47.1cm^2` Therefore, the curved surface area of the cone is `47.1cm^2`. Hence, option C, "47.1cm^2" is the correct answer.

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To solve the equation 5(x - 2) = (1 ÷ 125)(x + 3), we need to isolate the variable "x" on one side of the equation. First, let's simplify the right side of the equation: (1 ÷ 125)(x + 3) = (1 ÷ 125)x + (1 ÷ 125)3 = x/125 + 3/125 = (x + 3)/125 Now, let's simplify the left side of the equation: 5(x - 2) = 5x - 10 Now, we have: 5x - 10 = (x + 3)/125 To isolate "x" on one side, we'll multiply both sides by 125: 125 * 5x - 125 * 10 = 125 * (x + 3) / 125 Expanding the right side: 125 * 5x - 125 * 10 = x + 3 Combining like terms on the left side: 625x - 1250 = x + 3 Subtracting "x" from both sides: 624x - 1250 = 3 Adding 1250 to both sides: 624x = 1253 Dividing both sides by 624: x = 2 So the solution to the equation is x = 2, which is not equal to any of the options (-7/4, 4/7, or 7/4).

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2 + t/5(x + 3/5y ) = s
t/5(x + 3/5y ) = s − 2
[(t(5x + 3y) ÷ 25)] = s − 2
t(5x + 3y) = 25 (s − 2)
5x + 3y = [(25(s − 2))÷ t]
5x = [(25(s − 2))÷ t] − 3y
Divide both sides by 5
x = [25(s − 2) − 3ty)]÷ 5t

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The correct answer is 377.0cm^2. The formula for the surface area of a cylinder is given by: 2πr^2 + 2πrh where r is the radius of the base, h is the height of the cylinder, and π (pi) is a mathematical constant approximately equal to 3.14. In this case, r = 5cm and h = 7cm, so we can plug these values into the formula: 2π * 5^2 + 2π * 5 * 7 = 2π * 25 + 2π * 35 = 50π + 70π = 120π = 377.0cm^2 (rounded to one decimal place) So the total surface area of the cylinder is 377.0cm^2.

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Equation of a straight line is given by
$y-y_1=m(x-x_1)$
Where m is the slope or gradient
Don't forget, the line passes through the origin. That means it has a coordinates of $\left\{0,0\right\}$ and $\left\{-3,-4\right\}$. So to calculate m
$m=\frac{\Delta y}{\Delta x}=\frac{0-(-4)}{0-(-3)}=\frac{4}{3}$
Equation of straight line is therefore given as:
$y-(-4)=\frac{4}{3}[x-(-3\left)\right]$
$3(y+4)=4(x+3)$
$3y+12=4x+12$
$3y=4x$
$\therefore y=\frac{4x}{3}$

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One bag with 3 blue and 5 red
Pr (H) = 3/8Pr (r) 5/8
Another bag with 2 blue and 4 red (note one ball is drawn from each bag)
i.e. prob.=8 − 1 = 7
prob. (2 ball both are blue=pr (1st blue and 2nd blue)
prob. 2 balls both blue = 3/8 × 2/7
= $\frac{3}{28}$

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His annual salary = ₦2000
His allowances = ₦600
So his taxable income = Annual salary − allowance
= ₦2000 − ₦600
= ₦1400
He pays at 5%
Then, his allowance income tax 5/100 × 600 = ₦30

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The correct answer is (x + 5)(x + 4). This can be determined using the method of factoring by grouping. The general idea is to rewrite the expression as the product of two binomials (in this case, two linear expressions) that add up to the original expression. To do this, we need to find two numbers that multiply to give 20 and add up to 9. These numbers are 4 and 5. So, we write the expression as: (x + 5)(x + 4) = x^2 + 9x + 20 Therefore, (x + 5)(x + 4) is the factorized form of x^2 + 9x + 20.

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To evaluate log base 7 of 17, we need to find the exponent that 7 must be raised to in order to obtain 17. In other words, we need to solve the equation 7^x = 17. This cannot be done algebraically, so we must use numerical methods or a calculator to approximate the solution. Using a calculator, we find that 7^1.455 ≈ 16.999, and 7^1.456 ≈ 17.035. Therefore, log base 7 of 17 is approximately 1.455. So, the answer is: 1.455.

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132x = 708
$1\times x^2+3\times x^1+2\times x^0$
$7\times 8^1+0\times 8^0$
$x^2+3x+2-56=0$
$x^2+3x-54=0$
x(x + 9)−6(x + 9) = 0
(x + 9)(x − 6) = 0
Either (x + 9) = 0 or (x − 6) = 0
x = − 9 or +6
The positive values for x = 6
The base number for 132x = 1326

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If the man sold the car for ₦420,000 at a gain of 15%, then we can find the cost price of the car using the following formula: Selling price = Cost price + Profit We know the selling price is ₦420,000 and the profit is 15% of the cost price. Let's call the cost price "x." Profit = 15% of x = 0.15x Substituting the values in the formula: ₦420,000 = x + 0.15x ₦420,000 = 1.15x To solve for x, we need to divide both sides by 1.15: x = ₦420,000 / 1.15 x = ₦365,217.39 Therefore, the cost price of the car was ₦365,217.39. So, option B - ₦365,217 is the correct answer.

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The formula for finding the amount of interest earned on a principal amount is given as A = P(1 + (r ÷ 100))n, where P is the principal amount, r is the interest rate, and n is the number of years the money is invested for. Using the given values of P = 126, r = 4 and n = 2, we can plug these values into the formula and find A: A = 126 * (1 + (4 ÷ 100))^2 = 126 * (1 + 0.04)^2 = 126 * 1.04^2 = 126 * 1.0816 = 136.30 So, the amount A to which the principal of 126 amounts at 4% compound interest for 2 years is ₦136.30K.

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To find the rate per annum of simple interest, we can use the formula: Simple Interest = (Principal * Rate * Time) / 100 where Principal is the initial amount, Rate is the interest rate per annum, and Time is the time period in years. In this case, we know that the Principal is ₦525, the Simple Interest is ₦588 - ₦525 = ₦63, and the Time is 3 years. Substituting these values into the formula, we get: 63 = (525 * Rate * 3) / 100 Simplifying the equation, we get: Rate = (63 * 100) / (525 * 3) = 4% Therefore, the rate per annum of simple interest that will amount to ₦588 in 3 years is 4%.

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tan x = $\frac{2}{3}$(given), is illustrated in a right-angled $\Delta$
thus m2 = 22 + 32
= 4 + 9 = 13
m = $\sqrt{13}$
Hence, 2sin x = 2 x $\frac{2}{m}$
2 x$\frac{2}{\sqrt{13}}$
= $\frac{4}{\sqrt{13}}$
= $\frac{4}{\sqrt{13}}=\frac{\sqrt{13}}{\sqrt{13}}$
= $\frac{4\sqrt{13}}{13}$

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(159.75)10 = (y)6
$\begin{array}{cc}6& 159\\ 6& 26\text{R 3}\\ 6& 4\text{R 2}\\ & 0\text{R 4}\end{array}\uparrow$
15910 = 4236
Then Convert 0.75 to base 6
0.75 x 6 =4.5 i.e 4.5 - 3.00 = 1.5
0.5 x 6 = 3.00 423 + 1.5 =424.5
159.75 = (424.5)6
(159)10 = (424.5)6

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The correct answer is ₦20. To find the duty to be added to a bill of ₦80, we need to calculate 25% of ₦80. 25% means 25 out of 100, so we can calculate 25% of ₦80 by multiplying ₦80 by 25/100. ₦80 * 25/100 = ₦20 So the duty to be added to a bill of ₦80 is ₦20.

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The correct answer is 3 15/38. To simplify the expression 1 1/4 ÷ (2 ÷ 1/4 of 28), we need to perform the operations in the correct order. First, we need to calculate 2 ÷ 1/4 of 28: 2 ÷ 1/4 of 28 = 2 ÷ (1/4 * 28) = 2 ÷ 7 = 4/7 Next, we can divide 1 1/4 by 4/7: 1 1/4 ÷ 4/7 = (5/4) ÷ (4/7) = (5/4) * (7/4) = 35/4 = 8 3/4 So the answer is 8 3/4, which can be simplified to 3 15/38 by dividing both the numerator and denominator by the greatest common divisor of 15 and 38, which is 1. So the final answer is 3 15/38.

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To find the percentage birth rate, we need to divide the number of births by the total population and multiply by 100 to get the percentage. So, the birth rate would be (62/6250) x 100 = 0.992 x 100 = 0.992%. Therefore, the closest option to the birth rate would be 1.0%.