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.

1,436.

Find the quadratic equation whose roots are c and -c

A.

x2 - c2 = 0

B.

x2 + 2cx = 0

C.

x2 + 2cx + c2 = 0

D.

x2 - 2cx + c2 = 0

Correct answer is A

Explanation
Roots; x and -c

sum of roots = c + (-c) = 0

product of roots = c x -c = -c2

Equation; x2 - (sum of roots) x = product of roots = 0

x2 - (0)x + (-c2) = 0

x2 - c2 = 0

1,437.

If p = \(\frac{1}{2}\) and \(\frac{1}{p - 1} = \frac{2}{p + x}\), find the value of x

A.

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

B.

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

C.

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

D.

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

Correct answer is B

p = \(\frac{1}{2}; \frac{1}{p - 1} = \frac{2}{p + x}\)

\(\frac{1}{\frac{1}{2} - 1} = \frac{2}{\frac{1}{2} + x}\)

\(\frac{1}{\frac{1 - 2}{2}} = \frac{2}{\frac{1 + 2x}{2}}\)

\(\frac{1}{-\frac{1}{2}} = \frac{2}{\frac{1 + 2x}{2}}\)

-2 = \(\frac{4}{1 + 2x} -2(1 + 2x) = 4\)

1 + 2x = \(\frac{4}{-2}\)

1 + 2x = -2

2x = -2 - 1

2x = -3

x = -\(\frac{3}{2}\)

x = -1\(\frac{1}{2}\)

1,438.

XY is a chord of circle centre O and radius 7cm. The chord XY which is 8cm long subtends an angle of 120o at the centre of the circle. Calculate the perimeter of the minor segment. [Take \(\pi = \frac{22}{7}\)]

A.

14.67cm

B.

22.67cm

C.

29.33cm

D.

37.33cm

Correct answer is B

perimeter of minor segment = Length of arc xy + chord xy

where lxy = \(\frac{120}{360} \times 2x \times \frac{22}{7} \times 7\)

= 14.67cm

perimeter of minor segment = 14.67 + 8 = 22.67cm

1,439.

What is the length of an edge of a cube whose total surface area is X cm2 and whose total surface area is \(\frac{X}{2}\)cm3?

A.

3

B.

6

C.

9

D.

12

Correct answer is A

Total surface area of cube = 6s2

6s2 = x

s2 = x = \(\frac{x}{6}\).....(1)

volume of a cube = s2 = \(\frac{x}{2}\)

s2 = \(\frac{x}{2}\)......(2)

put(1) into (2)

s(\(\frac{x}{6}\)) = \(\frac{x}{2}\)

s = \(\frac{x}{2} \times \frac{6}{x}\)

= 3cm

1,440.

An arc of a circle, radius 14cm, is 18.33cm long. Calculate to the nearest degree, the angle which the arc subtends at the centre of the circle. [T = \(\frac{22}{7}\)]

A.

11o

B.

20o

C.

22o

D.

75o

Correct answer is D

Length of an arc = \(\frac{\theta}{360} \times 2\pi r\)

18.33 = \(\frac{\theta}{360} \times 2 \times \frac{22}{7} \times 14\)

\(\theta = \frac{18.33 \times 360 \times 17}{2 \times 22 \times 14}\)

= 75o (approx.)