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.

3,206.

The mean of 20 observations in an experiment is 4, lf the observed largest value is 23, find the mean of the remaining observations.

A.

4

B.

3

C.

2.85

D.

2.60

E.

2.56

Correct answer is B

Mean of 20 observations = 4

All the observations = 20 x 4 = 80

Largest observed value = 23

Remaining observation = 80 - 23 = 57

Mean of observation = 57/19 = 3

3,207.

What is the mode of the numbers 8, 10, 9, 9, 10, 8, 11, 8, 10, 9, 8 and 14?

A.

8

B.

9

C.

10

D.

11

E.

14

Correct answer is A

No explanation has been provided for this answer.

3,208.
3,209.

Without using tables, find the value of \(\frac{\sin 20°}{\cos 70°} + \frac{\cos 25°}{\sin 65°}\)

A.

2

B.

1

C.

0

D.

-1

E.

-2

Correct answer is A

Note: sin 20° = cos 70° hence

\(\frac{\sin 20}{\cos 70} = 1\)

Also, cos 65° = sin 25°

\(\frac{\cos 65}{\sin 25} = 1\)

\(\therefore \frac{\sin 20}{\cos 70} + \frac{\cos 65}{\sin 25}\)

= 1 + 1

= 2

3,210.

In ΔABC above, BC is produced to D, /AB/ = /AC/ and ∠BAC = 50o. Find ∠ACD

A.

50o

B.

60o

C.

65o

D.

100o

E.

115o

Correct answer is E

ACB = ABC [Base angles of isoceles triangle]
ACB + ABC + 50o = 180o[sum of angles in a triangle]
ACB + ABC = 180o - 50o = 130o

ACB
130o/2
= 65o

ACD + ACB = 180o[sum of ∠s on a straight line]
ACD + 65o = 180o
ACD = 180o - 65o = 115o