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.

2,151.

If x is the addition of the prime numbers between 1 and 6; and y the H.C.F. of 6, 9, 15. Find the product of x and y

A.

27

B.

30

C.

33

D.

90

Correct answer is B

Prime numbers between 1 and 6 are 2, 3 and 5 x = 2 + 3 = 5 = 10 H.C.F. of 6, 9, 15 = 3 ∴ y = 3 X x y = 10 x 3 = 30

2,153.
2,154.

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

2,155.

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)

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

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

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

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

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

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