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.

3,402.

A box contains 2 white and 3 blue identical marbles. If two marbles are picked at random, one after the other without replacement, what is the probability of picking two marbles of different colors?

A.

2/3

B.

3/5

C.

2/5

D.

7/20

E.

3/10

Correct answer is B

Total number of marbles = 5; 1st pick = 2/5 2nd pick = 3/4; 3rd pick = 3/5; 4th pick = 2/4
∴ Probability of picking two marbles of different colors = (2/5 x 3/4) + (3/5 + 2/4) = 12/20 = 3/5

3,403.

If events X and Y are mutually exclusive, P(X) = 1/3 and P(Y) = 2/5, P(X∪Y) is

A.

0

B.

2/15

C.

4/14

D.

11/15

E.

1

Correct answer is D

P(X \(\cup\) Y) = \(\frac{1}{3} + \frac{2}{5}\)

= \(\frac{11}{15}\)

3,404.

If events X and Y are mutually exclusive, . P(X) = 1/3 and P(Y) = 2/5, P(X∩Y) is

A.

0

B.

2/15

C.

11/15

D.

4/15

E.

1

Correct answer is B

P(X \(\cap\) Y) = \(\frac{1}{3} \times \frac{2}{5}\)

= \(\frac{2}{15}\)

3,405.

The mean of 30 observations recorded in an experiment is 5. lf the observed largest value of 34 is deleted, find the mean of the remaining observations

A.

5

B.

4

C.

3.9

D.

3.4

E.

3.0

Correct answer is B

x = 5, \(\frac{\sum {fx}}{\sum {f}}\) =

5= \(\frac{\sum {fx}}{30}\)

\(\sum {fx}\) = 5 x 30 = 150; 150 - 34 = 116

\(\sum {f}\) = 29
\(\sum {fx}\) = 116

= \(\frac{116}{29}\) = 4