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.

521.

A binary operation \(\otimes\) is defined by \(m \otimes n = mn + m - n\) on the set of real numbers, for all m, n \(\in\) R. Find the value of 3 \(\otimes\) (2 \(\otimes\) 4).

A.

6

B.

25

C.

15

D.

18

Correct answer is C

\(m \otimes n = mn + m - n\)

3 \(\otimes\) (2 \(\otimes\) 4)

2 \(\otimes\) 4 = 2(4) + 2 - 4 = 6

3 \(otimes\) 6 = 3(6) + 3 - 6  = 15

522.

The angle of elevation of the top of a tree from a point on the ground 60m away from the foot of the tree is 78°. Find the height of the tree correct to the nearest whole number.

A.

148m

B.

382m

C.

282m

D.

248m

Correct answer is C

\(\tan 78 = \frac{h}{60}\)

\(h = 60 \tan 78\)

\(h = 60 \times 4.705 = 282.27m\)

\(\approxeq\) 282m to the nearest whole number.

523.

Make q the subject of the formula in the equation \(\frac{mn}{a^2} - \frac{pq}{b^2} = 1\)

A.

\(q = \frac{b^2(mn - a^2)}{a^2 p}\)

B.

\(q = \frac{m^2 n - a^2}{p^2}\)

C.

\(q = \frac{mn - 2b^2}{a^2}\)

D.

\(q = \frac{b^2 (n^2 - ma^2)}{n}\)

Correct answer is A

\(\frac{mn}{a^2} - \frac{pq}{b^2} = 1\)

\(\frac{mn}{a^2} - 1 = \frac{pq}{b^2}\)

\(\frac{mn - a^2}{a^2} = \frac{pq}{b^2}\)

\(pq = \frac{b^2 (mn - a^2)}{a^2}\)

\(q = \frac{b^2(mn - a^2)}{a^2 p}\)

524.

The number line represents

A.

0 > x \(\geq\) -7

B.

-7 \(\leq\) x < -1

C.

-7 < x \(\leq\) -1

D.

-7 < x < -1

Correct answer is C

No explanation has been provided for this answer.

525.

In the diagram above, RST is a tangent to circle VSU center O ∠SVU = 50° and UV is a diameter. Calculate ∠RSV.

A.

90°

B.

50°

C.

45°

D.

40°

Correct answer is D

< VSU = 90° (angle in a semi-circle)

\(\therefore\) < SUV = 180° - 90° - 50°

= 40°

< RSV = 40° (angle which chord makes tangent = angle in alternate segment)