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.

1,191.

A cube and cuboid have the same base area. The volume of the cube is 64cm\(^3\) while that of the cuboid is 80cm\(^3\). Find the height of the cuboid

A.

1cm

B.

3cm

C.

5cm

D.

6cm

Correct answer is C

Volume of a cube with side a cm = a\(^3\)

a\(^3\) = 64 \(\implies\) a = 4cm

Base area of a cube = a\(^2\)

= 4\(^2\)

= 16 cm\(^2\)

\(\implies\) Base area of the cuboid = 16 cm\(^2\)

Volume of cuboid = Base area x height

80 = 16 x h

h = \(\frac{80}{16}\)

= 5 cm

1,192.

A chord is 2cm from the centre of a circle. If the radius of the circle is 5cm, find the length of the chord

A.

2\(\sqrt{21}\)cm

B.

\(\sqrt{42}\)cm

C.

2\(\sqrt{19}\)cm

D.

\(\sqrt{21}\)cm

Correct answer is A

From \(\bigtriangleup\) OMQ find /MQ/ by Pythagoras OQ2 = OM2 + MQ2

52 = 22 + MQ2

25 = 4 + MQ2

25 - 4 = MQ2

21 - MQ2

MQ2 = 21

MQ2 = \(\sqrt{21}\)

Length of chord = 2 x \(\sqrt{21}\) = 2\(\sqrt{21}\)cm

1,193.

Given that p\(\frac{1}{3}\) = \(\frac{3\sqrt{q}}{r}\), make q the subject of the equation

A.

q = p\(\sqrt{r}\)

B.

q = p3r

C.

q = pr3

D.

q = pr\(\frac{1}{3}\)

Correct answer is D

p\(\frac{1}{3}\) = \(\frac{3\sqrt{q}}{r}\)(cross multiply)

3\(\sqrt{q}\) = r x 3\(\frac{\sqrt{q}}{r}\)(cross multiply)

3\(\sqrt{q}\) = r x 3\(\sqrt{p}\) cube root both side

q = 3\(\sqrt{r}\) x p

q = r\(\frac{1}{3}\)p = pr\(\frac{1}{3}\)

1,194.

If \(\frac{1}{2}\)x + 2y = 3 and \(\frac{3}{2}\)x and \(\frac{3}{2}\)x - 2y = 1, find (x + y)

A.

3

B.

2

C.

1

D.

5

Correct answer is A

\(\frac{1}{2}\)x + 2y = 3......(i)(multiply by 2)

\(\frac{3}{2}\)x - 2y = 1......(ii)(multiply by 2)

x + 4y = 6......(iii)

3x - 4y = 2.....(iv) add (iii) and (iv)

4x = 8, x = \(\frac{8}{4}\) = 2

substitute x = 2 into equation (iii)

x + 4y = 6

2 + 4y = 6

4y = 6 - 2

4y = 4

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

= 1(x + y)

2 + 1 = 3

1,195.

If x = 64 and y = 27, evaluate: \(\frac{x^{\frac{1}{2}} - y^{\frac{1}{3}}}{y - x^{\frac{2}{3}}}\)

A.

2\(\frac{1}{5}\)

B.

1

C.

\(\frac{5}{11}\)

D.

\(\frac{11}{43}\)

Correct answer is C

\(\frac{x^{\frac{1}{2}} - y^{\frac{1}{3}}}{y - x^{\frac{2}{3}}}\)

substitute x = 64 and y = 27

\(\frac{64^{\frac{1}{2}} - 27^{\frac{1}{3}}}{27 - 64^{\frac{2}{3}}} = \frac{\sqrt{64} - 3\sqrt{27}}{27 - (3\sqrt{64})^2}\)

= \(\frac{8 - 3}{27 - 16}\)

= \(\frac{5}{11}\)