Mathematics Past Questions and Answers

The mean of the ages of ten secondary school pupils is 16 but when the age of their teacher is added to it the men becomes 19. Find the age of the teacher

A 27
B 35
C 38
D 49

Question 37:

\(\begin{array}{c|c} Class & Frequency\\ \hline 1 - 5 & 2\\6 - 10 & 4\\11 - 15 & 5\\16 - 20 & 2 \\ 21 - 25 & 3\\26 - 30 & 2\\31 - 35 & 1\\36 - 40 & 1 \end{array}\)
Find the median of the observation in the table given

A 11.5
B 12.5
C 14.0
D 14.5

Question 38:

A number is selected at random between 20 and 30, both numbers inclusive. Find the probability that the number is a prime

A \(\frac{2}{11}\)
B \(\frac{5}{11}\)
C \(\frac{6}{11}\)
D \(\frac{8}{11}\)

Question 39:

Calculate the standard deviation of the following data: 7, 8, 9, 10, 11, 12, 13.

A 2
B 4
C 10
D 11

Question 40:

The chances of three independent events X, Y, Z occurring are \(\frac{1}{2}\), \(\frac{2}{3}\), \(\frac{1}{4}\) respectively. What are the chances of Y and Z only occurring?

A \(\frac{1}{8}\)
B \(\frac{1}{24}\)
C \(\frac{1}{12}\)
D \(\frac{1}{4}\)