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.

641.

Evaluate ∫\(^2_1\) \(\frac{5}{x}\) dx

A.

1.47

B.

2.67

C.

3.23

D.

3.47

Correct answer is D

∫\(\frac{5}{x}\) dx = 5 ∫\(\frac{1}{x}\) = 5Inx

  Since the integral of \(\frac{1}{x}\) is Inx

  ∫\(^2\) \(_1\)∫ \(\frac{5}{x}\) dx = 5

  dx = 5 (In<2 – InIn1)

  = 3.4657

  = 3.47

642.

Calculate 243\(_{six}\) – 243\(_{five}\) expressing your answer in base 10

A.

0

B.

1

C.

26

D.

46

Correct answer is C

Since they are of different base, convert to base 10

  243\(_{six}\) = (2 x 62) + (4 x 61) + (3 x 60)

  = 72 + 24 + 3 = 99 base 10

  243\(_{six}\) = 2 x 52 + 4 x 51 +3 x 50

  50 + 20 + 3 = 73 base 10

  Subtracting them, 99 - 73

  = 26

643.

What is the modal age?

A.

4

B.

5

C.

6

D.

7

Correct answer is B

The modal age is the age with the highest frequency, and that is age 5 years with f of 7

644.

Find the average of the first four prime numbers greater than 10

A.

20

B.

19

C.

17

D.

15

Correct answer is D

Prime numbers are numbers that has only two factors (i.e 1 and itself). They are numbers that are only divisible by 1 and their selves. First four Prime numbers greater than 10 are 11, 13, 17 and 19

  Average = sum of numbers / number

  = \(frac{(11 + 13 + 17 + 19)}{4}\)

  = \(\frac{60}{4}\)

  = 15

 

645.

Given that Sin (5\(_x\) − 28)\(^o\) = Cos(3\(_x\) − 50)\(^o\), o < x < 90\(^o\)
Find the value of x

A.

14\(^o\)

B.

21\(^o\)

C.

32\(^o\)

D.

39\(^o\)

Correct answer is B

Sin(5x - 28) = Cos(3x - 50)………..i

  But Sinα = Cos(90 - α)

  So Sin(5x - 28) = Cos(90 - [5x - 28])

  Sin(5x - 28) = Cos(90 - 5x + 28)

  Sin(5x - 28) = Cos(118 - 5x)………ii

  Combining i and ii

  Cos(3x - 50) = Cos(118 - 5x)

  3x - 50 = 118 - 5x

  Collecting the like terms

  3x + 5x = 118 + 50

  8x = 168

  x = \(\frac{168}{8}\)

  x = 21\(^o\)

  Answer is B