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.

2,661.

The sum to infinity of a geometric progression is \(-\frac{1}{10}\) and the first term is \(-\frac{1}{8}\). Find the common ratio of the progression.

A.

\(-\frac{1}{5}\)

B.

\(-\frac{1}{4}\)

C.

\(-\frac{1}{3}\)

D.

\(-\frac{1}{2}\)

Correct answer is B

Sr = \(\frac{a}{1 - r}\)

\(-\frac{1}{10}\) = \(\frac{1}{8} \times \frac{1}{1 - r}\)

\(-\frac{1}{10}\) = \(\frac{1}{8(1 - r)}\)

\(-\frac{1}{10}\) = \(\frac{1}{8 - 8r}\)

cross multiply...

-1(8 - 8r) = -10

-8 + 8r = -10

8r = -2

r = -1/4

2,662.

The nth term of a sequence is n2 - 6n - 4. Find the sum of the 3rd and 4th terms.

A.

24

B.

23

C.

-24

D.

-25

Correct answer is D

n2 - 6n - 4

For the 3rd term,
32 - 6(3) - 4

9 - 18 -4 = -13

For the 4th term,
42 - 6(4) - 4

16 - 24 - 4 = -12

Sum of both terms

-13 - 12 = -25

2,663.

Find the range of values of m which satisfy (m - 3)(m - 4) < 0

A.

2 < m < 5

B.

-3 < m < 4

C.

3 < m < 4

D.

-4 < m < 3

Correct answer is C

(m - 3)(m - 4) < 0

(m - 3) < 0 ; (m - 4) < 0

m < 3 ; m < 4

3 < m < 4

2,664.

The value of y for which \(\frac{1}{5}y + \frac{1}{5} < \frac{1}{2}y + \frac{2}{5}\) is

A.

\(y > \frac{2}{3}\)

B.

\(y < \frac{2}{3}\)

C.

\(y > -\frac{2}{3}\)

D.

\(y < -\frac{2}{3}\)

Correct answer is C

\(\frac{1}{5}y + \frac{1}{5} < \frac{1}{2}y + \frac{2}{5}\)

Collect like terms

\(\frac{y}{5} - \frac{y}{2} < \frac{2}{5} - \frac{1}{5}\)

\(\frac{2y - 5y}{10} < \frac{2 - 1}{5}\)

\(\frac{-3y}{10} < \frac{1}{5}\)

\(y > \frac{-2}{3}\)

2,665.

U is inversely proportional to the cube of V and U = 81 when V = 2. Find U when V = 3

A.

24

B.

27

C.

32

D.

36

Correct answer is A

U \(\propto \frac{1}{V^3}\)

U = \(\frac{k}{V^3}\)

k = UV\(^3\)

k = 81 x 2\(^3\) = 81 x 8

When V = 3,

U = \(\frac{k}{V^3}\)

U = \(\frac{81 \times 8}{3^3}\)

U = \(\frac{81 \times 8}{27}\) = 24