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.

2,286.

If the exterior angles of a pentagon are x°, (x + 5)°, (x + 10)°, (x + 15)° and (x + 20)°, find x

A.

118o

B.

72o

C.

62o

D.

36o

Correct answer is C

The sum of the exterior angles of a regular polygon = 360°.

\(\therefore x + (x + 5) + (x + 10) + (x + 15) + (x + 20) = 360°\)

\(5x + 50 = 360° \implies 5x = 360° - 50° = 310°\)

\(x = \frac{310°}{5} = 62°\)

2,287.

One angle of a rhombus is 60o. The shorter of the two diagonals is 8cm long. Find the length of the longer one.

A.

8\(\sqrt{3}\)

B.

\(\frac{16}{\sqrt{3}}\)

C.

\(\sqrt{3}\)

D.

\(\frac{10}{\sqrt{3}}\)

Correct answer is A

\(\frac{x}{4}\) = \(\frac{\tan 60}{1}\)

x = 4 tan60

= 4\(\sqrt{3}\)

BD = 2x

= 8\(\sqrt{3}\)

2,288.

The area of a square is 144 sq cm. Find the length of its diagonal

A.

11\(\sqrt{3cm}\)

B.

12cm

C.

12\(\sqrt{2cm}\)

D.

13cm

Correct answer is C

BD = \(\sqrt{x^2 + x^2}\)

= \(\sqrt{12^2 + 12^2}\)

= \(\sqrt{144 + 144}\)

= 2(144)

= 12\(\sqrt{2cm}\)

2,289.

Find the sum of the first 20 terms in an arithmetic progression whose first term is 7 and last term is 117.

A.

2480

B.

1240

C.

620

D.

124

Correct answer is B

Given the first and last term of an A.P, the sum of the terms is given by

\(S_{n} = \frac{n}{2} [a + l]\)

where a = first term; l = last term and n = number of terms.

\(\therefore S_{20} = \frac{20}{2} [7 + 117]\)

= \(10 (124)\)

= 1240

2,290.

At what value of x is the function y = x2 - 2x - 3 minimum?

A.

1

B.

-1

C.

-4

D.

4

Correct answer is A

For y = ax2 - bx + c for minimum y

\(\frac{dy}{dx}\) = 2x - 2

= \(\frac{dy}{dx}\) = 0

∴ 2x - 2 = 0

x = 1