Mathematics questions and answers

Mathematics Questions and Answers

How good are you with figures and formulas? Find out with these Mathematics past questions and answers. This Test is useful for both job aptitude test candidates and students preparing for JAMB, WAEC, NECO or Post UTME.

471.

A binary operation Δ is defined by a Δ b = a + 3b + 2.
Find (3 Δ 2) Δ 5

A.

35

B.

59

C.

28

D.

87

Correct answer is C

a Δ b = a + 3b + 2 (3 Δ 2) Δ 5 = (3 + 3(2) + 2) Δ 5 = 11 Δ 5 = 11 + 3(5) + 2 = 28

472.

A factory worker earns ₦50,000 per month out of which he spends 15% on his children's education, ₦13,600 on Food, 3% on electricity and uses the rest for his personal purpose. How much does he have left?

A.

N21,850

B.

N18,780

C.

N27,400

D.

N32,500

Correct answer is C

Education = \(\frac{15}{100} \times N 50,000\)

= N 7,500

Food = N 13,600

Electricity = \(\frac{3}{100} \times N 50,000\)

= N 1,500

Leftover : N (50,000 - (7,500 + 13,600 + 1,500))

= N 27,400

473.

Find the equation of the locus of a point A(x, y) which is equidistant from B(0, 2) and C(2, 1)

A.

4x + 2y = 3

B.

4x - 3y = 1

C.

4x - 2y = 1

D.

4x + 2y = -1

Correct answer is C

Since A(x, y) is the point of equidistance between B and C, then 

AB = AC

(AB)\(^2\) = (AC)\(^2\)

Using the distance formula, 

(x - 0)\(^2\) + (y - 2)\(^2\) = (x - 2)\(^2\) + (y - 1)\(^2\)

x\(^2\) + y\(^2\) - 4y + 4 = x\(^2\) - 4x + 4 + y\(^2\) - 2y + 1

x\(^2\) - x\(^2\) + y\(^2\) - y\(^2\) + 4x - 4y + 2y = 5 - 4

4x - 2y = 1

474.

A bricklayer charges ₦1,500 per day for himself and ₦500 per day for his assistant. If a two bedroom flat was built for ₦95,000 and the bricklayer worked 10 days more than his assistant, how much did the assistant receive?

A.

N20,000

B.

N28,000

C.

N31,200

D.

N41,000

Correct answer is A

Let the number of days worked by the assistant = t

∴∴ The bricklayer worked (t + 10) days.

1500(t + 10) + 500(t) = N 95,000

1500t + 15,000 + 500t = N 95,000

2000t = N 95,000 - N 15,000

2000t = N 80,000

t = 40 days

∴∴ The assistant worked for 40 days and received N (500 x 40)

= N 20,000

475.

If \(25^{1 - x} \times 5^{x + 2} \div (\frac{1}{125})^{x} = 625^{-1}\), find the value of x.

A.

x = -4

B.

x = 2

C.

x = -2

D.

x = 4

Correct answer is A

\(25^{1 - x} \times 5^{x + 2} \div (\frac{1}{125})^{x} = 625^{-1}\)

\((5^2)^{(1 - x)} \times 5^{(x + 2)} \div (5^{-3})^x = (5^4)^{-1}\)

\(5^{2 - 2x} \times 5^{x + 2} \div 5^{-3x} = 5^{-4}\)

\(5^{(2 - 2x) + (x + 2) - (-3x)} = 5^{-4}\)

Equating bases, we have

\(2 - 2x + x + 2 + 3x = -4\)

\(4 + 2x = -4 \implies 2x = -4 - 4\)

\(2x = -8\)

\(x = -4\)