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.

781.

Two angles of a pentagon are in the ratio 2:3. The others are 60o each. Calculate the smaller of the two angles

A.

72o

B.

100o

C.

120o

D.

144o

Correct answer is D

The diagram given simple illustrates that a pentagon contains three \(\Delta\)s.

Two angles which are in the ratio 2:3 will have actual values 2xo, 3xo respectively. Thus 2xo + 3xo + 3 x 60 = 3x sum of angles of \(\Delta\)a

i.e. 5xo + 180o = 3 x 180o

5xo + 180o = 540o

5xo = 540o - 180o

5xo = 360o

xo = \(\frac{360^o}{5}\)

= 72o

Hence, the smaller of the two angles is

2 x 72o = 144o

782.

In the diagram, the shaded part is carpet laid in a room with dimensions 3.5m by 2.2m leaving a margin of 0.5m round it. Find area of the margin

A.

4.7m2

B.

4.9m2

C.

5.7m2

D.

5.9m2

Correct answer is A

Area of floor = 3.5m x 2.2m = 7.7m2

Area of carpet = (3.5 - 0.5 - 0.5)m x (2.2 - 0.5 - 0.5)m

2.5m x 1.2m = 3m2

hence, area of margine

= area of floor - area of carpet

= (7.7 - 3)m2

= 4.7m2

783.

Calculate the mean deviation of 5, 3, 0, 7, 2, 1

A.

0.0

B.

2.0

C.

2.5

D.

3.0

Correct answer is B

mean = \(\bar{x}\) = \(\frac{\sum x}{n}\)

= \(\frac{5 + 3 + 0 + 7 + 2 + 1}{6}\)

\(\frac{18}{6}\) = 3

\(\begin{array}{c|c}
x & x - \bar{x} & |x - \bar{x}|\\ \hline 5 & -2 & 2 \\ \hline 3 & 0 & 0 \\ \hline 0 & -3 & 3 \\ \hline 7 & 4 & 4 \\ \hline 2 & -1 & 1 \\ \hline 1 & -2 & 2 \\ \hline & & & \sum|x - \bar{x}| \\ \hline & & & 12
\end{array}\)

hence, MD = \(\frac{\sum|x - \bar{x}}{n}|\)

\(\frac{12}{6}\)

= 2

784.

Find the value of p if \(\frac{1}{4}\)p + 3q = 10 and 2p - q = 7

A.

4

B.

3

C.

-3

D.

-4

Correct answer is A

\(\frac{1}{4}\)p + 3p = 10...(1)

2p - \(\frac{1}{3}\)q = 7...(2)

Multiply equation (2) by 3 to clear fraction

3 x 2p - 3 x \(\frac{1}{3}\)q = 3 x 7

6p - q = 21

6p - 21 = q....(3)

substituting 6p - 21 for q in (1)

\(\frac{1}{4}\)p + 3(6p - 21) = 10...(4)

Multiply equation (4) by 4 to clear fraction

4 x \(\frac{1}{4}\)p + 4 x 3(6p - 21) = 4 x 10

p + 12(6p - 21) = 40

p + 72p - 252

73p = 292

p = \(\frac{292}{73}\)

= 4

785.

Describe the shaded portion in the diagram

A.

P' \(\cap\) Q \(\cap\) R'

B.

(P' \(\cap\) R)' \(\cap\) R

C.

P' \(\cap\) Q \(\cap\) R

D.

(P \(\cap\) Q)' \(\cap\) R

Correct answer is A

No explanation has been provided for this answer.