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.

636.

A box contains two red balls and four blue balls. A ball is drawn at random from the box and then replaced before a second ball is drawn. Find the probability of drawing two red balls.

A.

\(\frac{2}{3}\)

B.

\(\frac{1}{3}\)

C.

\(\frac{1}{4}\)

D.

\(\frac{1}{9}\)

Correct answer is D

Total number of balls = 2 + 4 = 6

  P(of picking a red ball) = \(\frac{2}{6}\) = \(\frac{1}{3}\)

  P(of picking a blue ball) = \(\frac{4}{6}\) = \(\frac{2}{3}\)

  With replacement,

  P( picking two red balls) = \(\frac{1}{3}\) × \(\frac{1}{3}\) = \(\frac{1}{9}\)

637.

if y = 23\(_{five}\) + 101\(_{three}\) find y leaving your answer in base two

A.

1110

B.

10111

C.

11101

D.

111100

Correct answer is B

First we convert the numbers to base ten

  23\(_{five}\)= 2 x 51 + 3 x 50

  = 10 + 3 = 13

  101\(_{five}\) = (1 x 32) + (0 x 31) + (1 x 30)

  = 9 + 0 + 1 = 10

  So, y = 13 + 10 = 23

  To convert 23 to base 2 (as in the diagram above)

Y = 23

  = 10111\(_{five}\)

Answer is B

638.

From a point P, Q is 5km due West and R is12km due South of Q. Find the distance between P and R.

A.

5km

B.

12km

C.

13km

D.

17km

Correct answer is C

Using Pythagoras theorem

  PR\(^2\) = 5\(^2\) + 12\(^2\)

  25 + 144 = 169

  PR = √(169)= 13km

 

639.

Out of 7 consonants and 4 vowels, how many words of 3 consonants and 2 vowels can be formed?

A.

210

B.

1050

C.

21400

D.

25200

Correct answer is A

To form words having 3 consonants and 2 vowels out of 7 consonants and 4 vowels, the number of such words is 7/3C x 4/2C = 35 x 6

  = 210

640.

Tossing a coin and rolling a die are two separate events. What is the probability of obtaining a tail on the coin and an even number on the die?

A.

\(\frac{1}{16}\)

B.

\(\frac{1}{6}\)

C.

\(\frac{1}{4}\)

D.

\(\frac{3}{8}\)

Correct answer is C

P( tail on a coin) = \(\frac{1}{2}\)

  Even numbers on a care 2, 4 and 6

  P( even number on a die) = \(\frac{3}{6}\) = \(\frac{1}{2}\)

  P( tail on a coin and even number on a die) = \(\frac{1}{2}\) x \(\frac{1}{2}\) = \(\frac{1}{4}\)