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.

1,131.

If x + y = 90 simplify \((sinx + siny)^2\)−2sinxsiny

A.

1

B.

0

C.

2

D.

-1

Correct answer is A

Given: \(x + y = 90° ... (1)\)

\((\sin x + \sin y)^{2} - 2\sin x \sin y = \sin^{2} x + \sin^{2} y + 2\sin x \sin y - 2\sin x \sin y\)

= \(\sin^{2} x + \sin^{2} y ... (2)\)

Recall: \(\sin x = \cos (90 - x) ... (a)\)

From (1), \(y = 90 - x ... (b)\)

Putting (a) and (b) in (2), we have

\(\sin^{2} x + \sin^{2} y \equiv \cos^{2} (90 - x) + \sin^{2} (90 - x)\)

= 1

1,132.

Find the total surface area of a cylinder of base radius 5cm and length 7cm ( π = 3.14)

A.

17.8cm2

B.

15.8cm2

C.

75.4cm2

D.

54.7cm2

E.

\(377.0cm^{2}\)

Correct answer is E

The total surface area of a cylinder = 2πrl + 2πr2

= 2πr(l + r)

= 2 × 3.14 x 5(7+5)

2 × 3.14 × 12 x 5

= 377.1cm (1DP)

1,133.

Simplify log101.5 + 3 log102 − log100.3

A.

log104

B.

log1040

C.

log10-40

D.

log104-

Correct answer is B

log101.5 + 3 log102 − log100.3

log101.5 + log1023 − log100.3

[log10(1.5 × 23) ÷ log100.3]

[log10(15/10 × 8 ) ÷ log10( 3/10)]

log10(15/10 × 8 × 10/3 )

log1040

1,134.

Find the x and z intercepts of the graph of 3x - z \(\leq\) 9

A.

(3, -9)

B.

(-3, 9)

C.

(-3, -9)

D.

(-3, 0)

Correct answer is A

Starting from 3x − z \(\leq\) 9

x = 0, substitute the value of x (i.e. x = 0) into the equation 3x − z \(\leq\) 9

3(0) − z \(\leq\) 9

z \(\leq\) − 9

If z = 0

Then, 3x − 0 \(\leq\) 9

3x \(\leq\) 9

x \(\leq\) 3

Intercept of x and z i.e (x,z)

= (3, -9)

1,135.

X and Y are two sets such that n(X) = 15, n(Y) = 12 and n{X ∩ Y} = 7. Find ∩{X ∪ Y}

A.

21

B.

225

C.

15

D.

20

Correct answer is D

n(X ∪ Y) = n(X) + n(Y) − n(X ∩ Y) = 15 + 12 − 7 ∴ n(X ∪ Y) = 20