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.

41.

Simplify \(3\sqrt{12} + 10\sqrt{3} - \frac{6}{\sqrt{3}}\)

A.

10\(\sqrt{3}\)

B.

18\(\sqrt{3}\)

C.

14\(\sqrt{3}\)

D.

7\(\sqrt{3}\)

Correct answer is C

\(3\sqrt{12} + 10\sqrt{3} - \frac{6}{\sqrt{3}}\)

= \(3\sqrt{4\times3} + 10\sqrt{3} - \frac{6}{\sqrt{3}}\)

= \(6\sqrt{3} + 10\sqrt{3} - \frac{6}{\sqrt{3}}\)

treating  like a fraction, then 

= \(\frac{18 + 30 - 6}{\sqrt{3}}\)

= \(\frac{42}{\sqrt{3}}\)

rationalizing 

= \(14\sqrt{3}\)

42.

In the diagram above, M, N, R are points on the circle centre O. ∠ORN = 48° and ∠RNM = 124°. Find ∠OMN.

A.

\(58^0\)

B.

\(64^0\)

C.

\(48^0\)

D.

\(76^0\)

Correct answer is D

Reflex ∠MOR = 2 × 124° = 248° (angle at the centre is twice the angle at the circumference)
∠MOR = 360° - 248° = 112° (sum of angle at a point is 360°)
∠OMN = 360° - (124°+ 48° + 112°) (sum of angles in a quadrilateral is 360°)
= 360° - 284°
∴ ∠OMN = 76°

43.

One-third of the sum of two numbers is 12, twice their difference is 12. Find the numbers.

A.

22 and 14

B.

20 and 16

C.

21 and 15

D.

23 and 13

Correct answer is C

Let the two numbers be x and y 

\(\frac{1}{3}( x + y) = 12\)

then x + y = 36 ..........i

2( x - y) = 12

x - y = 6 ............ii

add equations i and ii 

2x = 42

x = 21, put x = 21 into equation i

x + y = 36

21 + y = 36 

y = 36 - 21 = 15

therefore the numbers are 21 and 15

44.

The angle of elevation of the top of a building from a point Z on the ground is 50°. If the height of the building is 124 m, find the distance from Z to the foot of the building.

A.

147.78m

B.

104.05m

C.

161.87m

D.

192.91m

Correct answer is B

From the diagram above; Tan\(\theta = \frac{opp}{adj}\)

tan50° = \(\frac{124}{d}\)

d = \(\frac{124}{tan50}\)

therefore, d = 104.05m

45.

Mr Manu is 4 times as old as his son, Adu. 7 years ago the sum of their ages was 76. How old is Adu?

A.

22years

B.

12years

C.

18years

D.

15 years

Correct answer is C

Let Mr Manu be x years old and Adu be y years old.

But Mr Manu is four times as old as Adu then, x = 4y.

7 years ago, the sum of their ages was 76.

( x - 7) + ( y - 7) = 76

x + y - 14 = 76 

x + y = 76 + 14 = 90

But x = 4y 

Therefore, 4y + y = 90

5y = 90 

y = \(\frac{90}{5}\)

y = 18

Therefore Adu is 18 years old.