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.

2,186.
2,187.

Find correct to one decimal place, 0.24633 \(\div\) 0.0306

A.

0.8

B.

1.8

C.

8.0

D.

8.1

Correct answer is D

\(\frac{0.24633}{0.03060}\) multiplying throughout by 100,000

= \(\frac{24633}{3060}\)

= 8.05

= 8.1

2,188.

If 7 and 189 are the first and fourth terms of geometric progression respectively, find the sum of the first three terms of the progression

A.

182

B.

91

C.

63

D.

28

Correct answer is B

\(T_{n} = ar^{n - 1}\) (nth term of a G.P)

\(T_{4} = ar^{3} = 189\)

\(7 \times r^{3} = 189 \implies r^{3} = 27\)

\(r = \sqrt[3]{27} = 3\)

\(S_{n} = \frac{a(r^{n} - 1)}{r - 1}\)

\(S_{3} = \frac{7(3^{3} - 1)}{3 - 1} \)

= \(\frac{7 \times 26}{2} = 91\)

2,189.

If the sum of the 8th and 9th terms of an arithmetic progression is 72 and the 4th term is -6, find the common difference

A.

4

B.

8

C.

6\(\frac{2}{3}\)

D.

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

Correct answer is D

Let the first term and common difference = a & d respectively.

\(T_{n} = \text{nth term} = a + (n - 1) d\) (A.P)

Given: \(T_{4} = -6 \implies a + 3d = -6 ... (i)\)

\(T_{8} + T_{9} = 72\)

\(\implies a + 7d + a + 8d = 72 \implies 2a + 15d = 72 ... (ii)\)

From (i), \(a = -6 - 3d\)

\(\therefore\) (ii) becomes \(2(-6 - 3d) + 15d = 72\)

\(-12 - 6d + 15d = 72 \implies 9d = 72 + 12 = 84\)

\(d = \frac{84}{9} = 9\frac{1}{3}\)

2,190.

The solutions of x2 - 2x - 1 = 0 are the points of intersection of two graphs. if one of the graphs is y = 2 + x - x2, find the second graph

A.

y = 1 - x

B.

y = 1 + x

C.

y = x - 1

D.

y = 3x + 3

Correct answer is A

The second graph is 

\((x^{2} - 2x - 1) + (2 + x - x^{2})\)

= \(1 - x\)