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.

386.

A surveyor walks 500m up a hill which slopes at an angle of 30\(^o\). Calculate the vertical height through which he rises

A.

252m

B.

500m

C.

250m

D.

255m

Correct answer is C

\(\frac{h}{500}\) = sin 30\(^o\) 

= 500 sin 30\(^o\) 

= 500 x \(\frac{1}{2}\) 

= 250m 

387.

The mean age group of some students is 15years. When the age of a teacher, 45 years old, is added to the ages of the students, the mean of their ages become 18 years. Find the number of students in the group. 

A.

7

B.

9

C.

15

D.

42

Correct answer is B

x \(\frac{\sum x}{N}\)

15 = \(\frac{\sum x }{N}\)

\(\sum x\) = 15N........(i)

y = \(\frac{\sum y}{Ny} = \frac{\sum x + 45}{N + 1}\)

\(\frac{18}{1} = \frac{15N + 45}{N + 1}\) 

18(N + 1) = 15N + 45

18N + 18 = 15N + 45

18N - 15N = 45 - 18 

3N = 27 

N = \(\frac{27}{3}\) 

= 9

388.

The sum of the interior angle of pentagon is 6x + 6y. Find y in terms of x.

A.

y = 6 - x

B.

y = 90 - x

C.

y = 120 - x

D.

y = 150 - x

Correct answer is B

Sum of interior angles = (2n - 4) 90\(^o\) 

For perntagon, n = 5 

Sum of interior angles = 6 x 90\(^o\) = 540\(^o\) 

6x + 6y = 540\(^o\) 

6(x + y) = 540\(^o\) 

x + y = \(\frac{540^o}{6}\) = 90\(^o\) 

y = 90\(^o\) 

y = 90 - x

390.

Three consecutive terms of a geometric progression are give as n - 2, n and n + 3. Find the common ratio 

A.

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

B.

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

C.

\(\frac{1}{2}\)

D.

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

Correct answer is A

\(\frac{h}{n - 2} = \frac{n + 3}{n}\)

n\(^2\) = (n + 3) (n - 2) 

n\(^2\) = n\(^2\) + n - 6

n\(^2\) + n - 6 - n\(^2\) = 0

n - 6 = 0

n = 6

Common ratio: \(\frac{n}{n - 2} = \frac{6}{6 - 2} = \frac{6}{4}\) = \(\frac{3}{2}\)