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.

2,596.

Find r, if 6r7\(_8\) = 511\(_9\)

A.

3

B.

2

C.

6

D.

5

Correct answer is A

6r7\(_8\) = 511\(_9\)

6 x 8\(^2\) + r x 8\(^1\) + 7 x 8\(^0\) = 5 x 9\(^2\) + 1 x 9\(^1\) + 1 x 9\(^0\)

6 x 64 + 8r + 7 x 1 = 5 x 81 + 9 + 1 x 1

384 + 8r + 7 = 405 + 9 + 1

 

8r = 415 - 391

 8r = 24

r = \(\frac{24}{8}\)

= 3

2,597.

Find the derivative of \(\frac {\sin\theta}{\cos\theta}\)

A.

sec2 \(\theta\)

B.

tan \(\theta\) cosec \(\theta\)

C.

cosec \(\theta\)sec \(\theta\)

D.

cosec2\(\theta\)

Correct answer is A

\(\frac {\sin\theta}{\cos\theta}\)

\(\frac{\cos \theta {\frac{d(\sin \theta)}{d \theta}} - \sin \theta {\frac{d(\cos \theta)}{d \theta}}}{\cos^2 \theta}\)

\(\frac{\cos \theta. \cos \theta - \sin \theta (-\sin \theta)}{cos^2\theta}\)

\(\frac{cos^2\theta + \sin^2 \theta}{cos^2\theta}\)

Recall that sin2 \(\theta\) + cos2 \(\theta\) = 1

\(\frac{1}{\cos^2\theta}\) = sec2 \(\theta\)

2,598.

Find the probability that a number picked at random from the set(43, 44, 45, ..., 60) is a prime number.

A.

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

B.

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

C.

\(\frac{2}{9}\)

D.

\(\frac{7}{9}\)

Correct answer is C

Prime numbers = (43,47,53,59)

N = (43, 44, 45,..., 60)

The universal set contains 18 numbers.

The prime numbers between 43 and 60 are 4

Probability of picking a prime number = \(\frac{4}{18}\)

= \(\frac{2}{9}\)

2,599.

In how many ways can five people sit round a circular table?

A.

24

B.

60

C.

12

D.

120

Correct answer is A

The first person will sit down and the remaining will join. i.e. (n - 1)! = (5 - 1)! = 4! = 24 ways

2,600.

In how many was can the letters of the word ELATION be arranged?

A.

6!

B.

7!

C.

5!

D.

8!

Correct answer is B

ELATION Since there are 7 letters. The first letter can be arranged in 7 ways, , the second letter in 6 ways, the third letter in 5 ways, the 4th letter in four ways, the 3rd letter in three ways, the 2nd letter in 2 ways and the last in one way. therefore, 7 x 6 x 5 x 4 x 3 x 2 x 1 = 7! ways