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.

271.

What is the n-th term of the sequence 2, 6, 12, 20...?

A.

4n - 2

B.

2(3n - 1)

C.

n2 + n

D.

n2 + 3n + 2

Correct answer is C

Given that 2, 6, 12, 20...? the nth term = n\(^2\) + n

check: n = 1, u1 = 2

n = 2, u2 = 4 + 2 = 6

n = 3, u3 = 9 + 3 = 12

∴ n = 4, u4 = 16 + 4 = 20

272.

The angles of a quadrilateral are 5x-30, 4x+60, 60-x and 3x+61.find the smallest of these angles​

A.

5x - 30

B.

4x + 60

C.

60 - x

D.

3x + 61

Correct answer is C

Sum of all 4 angles of a quadrilateral = 360°

(5x-30) + (3x + 61) + (60-x) + (4x+ 60) = 360°

11x + 151 = 360°

11x = 360 - 151 = 209

x = 209/11 = 19°

Each angles is :

5x - 30 =  65°

4x+ 60 = 136°

60 - x =41°

3x + 61 = 118°

 

Smallest of these angles is 41° 

273.

Factorize m\(^3\) - m\(^2\) + 2m - 2

A.

(m2 + 1)(m - 2)

B.

(m - 1)(m + 1)(m + 2)

C.

(m - 2)(m + 1)(m - 1)

D.

(m2 + 2)(m - 1)

Correct answer is D

Using trial expansion of each option

(m\(^2\) + 2) (m - 1)

274.

If g(x) = x\(^2\) + 3x  find g(x + 1) - g(x)

A.

(x + 2)

B.

2(x + 2)

C.

(2x + 1)

D.

(x2 + 4)

Correct answer is B

g(x) = x2 + 3x

When g(x + 1) = (x + 1)^2 + 3(x + 1) 

= x\(^2\) + 1 + 2x + 3x + 3 

= x\(^2\) + 5x + 4

g(x + 1) - g(x) = x2 + 5x + 8 - (x\(^2\) + 3x)

= x\(^2\) + 5x + 4 - x2 -3x 

= 2x + 4 or 2(x + 4)

= 2(x + 2)

275.

If w varies inversely as \(\frac{uv}{u + v}\) and w = 8 when

u = 2 and v = 6, find a relationship between u, v, w.

A.

uvw = 16(u + v)

B.

16uv = 3w(u + v)

C.

uvw = 12(u + v)

D.

12uvw = u + v

Correct answer is C

W \(\alpha\) \(\frac{\frac{1}{uv}}{u + v}\)

∴ w = \(\frac{\frac{k}{uv}}{u + v}\)

= \(\frac{k(u + v)}{uv}\)

w = \(\frac{k(u + v)}{uv}\)

w = 8, u = 2 and v = 6

8 = \(\frac{k(2 + 6)}{2(6)}\)

= \(\frac{k(8)}{12}\)

k = 12

i.e 12 ( u + v) = uwv