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.

2,666.

If y varies directly as \(\sqrt{n}\) and y = 4 when n = 4, find y when n = 1\(\frac{7}{9}\)

A.

\(\sqrt{17}\)

B.

\(\frac{4}{3}\)

C.

\(\frac{8}{3}\)

D.

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

Correct answer is C

y \(\propto \sqrt{n}\)

y = k\(\sqrt{n}\)

when y = 4, n = 4
4 = k\(\sqrt{4}\)

4 = 2k

k = 2

Therefore,

y = 2\(\sqrt{n}\)

y = 2\(\sqrt{\frac{16}{9}}\)

y = 2\((\frac{4}{3})\)

y = \(\frac{8}{3}\)

2,667.

Solve for x and y in the equations below
x2 - y2 = 4
x + y = 2

A.

x = 0, y = -2

B.

x = 0, y = 2

C.

x = 2, y = 0

D.

x = -2, y = 0

Correct answer is C

x2 - y2 = 4 .... (1)
x + y = 2 .... (2)

Simplify eqn (1)

(x + y)(x - y) = 4

From eqn (2)
x + y = 2 so substitute it into simplified eqn (1), we have

2 (x - y) = 4

therefore,
x - y = 2 ... (1)
x + y = 2
---------
2x = 4
---------

x = 2, when y = 0

2,668.

Find the remainder when 2x3 - 11x2 + 8x - 1 is divided by x + 3

A.

-871

B.

-781

C.

-187

D.

-178

Correct answer is D

Hence f(x) = 2x3 - 11x2 + 8x - 1

f(-3) = 2(-3)3 - 11(-3)2 + 8(-3) - 1

= 2(-27) - 11(9) + 8(-3) - 1

= -54 - 99 - 24 - 1

= -178

2,669.

Make 'n' the subject of the formula if w = \(\frac{v(2 + cn)}{1 - cn}\)

A.

\(\frac{1}{c}(\frac{w - 2v}{v + w})\)

B.

\(\frac{1}{c}(\frac{w - 2v}{v - w})\)

C.

\(\frac{1}{c}(\frac{w + 2v}{v - w})\)

D.

\(\frac{1}{c}(\frac{w + 2v}{v + w})\)

Correct answer is A

w = \(\frac{v(2 + cn)}{1 - cn}\)

2v + cnv = w(1 - cn)

2v + cnv = w - cnw

2v - w = -cnv - cnw

Multiply through by negative sign

-2v + w = cnv + cnw

-2v + w = n(cv + cw)

n = \(\frac{-2v + w}{cv + cw}\)

n = \(\frac{1}{c}\frac{-2v + w}{v + w}\)

Re-arrange...

n = \(\frac{1}{c}\frac{w - 2v}{v + w}\)

2,670.

In a class of 46 students, 22 play football and 26 play volleyball. If 3 students play both games, how many play neither?

A.

1

B.

2

C.

3

D.

4

Correct answer is A

n(f \(\cap\) v) + n(f) + n(v) + n(f \(\cap\) v) = 46

3 + 19 + 23 + x = 46

22 + 23 + x = 46

45 + x = 46

x = 46 - 45

x = 1