STATISTICS - Jamb Mathematics Past Questions and Answers

Question 136:

• JAMB 1990

The mean of ten positive numbers is 16. When another number is added, the mean becomes 18. Find the eleventh number

A. 3
B. 16
C. 18
D. 38

Question 137:

• JAMB 1990

Below are the scores of a group of students in a test
\(\begin{array}{c|c} Scores & 1 & 2 & 3 & 4 & 5 & 6 \\ \hline \text{No. of students} & 1 & 4 & 5 & 6 & x & 2\end{array}\)
If the average scores is 3.5, find the value of x

A. 1
B. 2
C. 3
D. 4

Question 138:

• JAMB 1990

Two numbers are removed at random from the numbers 1, 2, 3 and 4. What is the probability that the sum of the numbers removed is even?

A. \(\frac{2}{3}\)
B. \(\frac{2}{15}\)
C. \(\frac{1}{2}\)
D. \(\frac{1}{4}\)

Question 139:

• JAMB 1990

Find the probability that a number selected at random from 41 to 56 is a multiply of 9

A. \(\frac{1}{8}\)
B. \(\frac{2}{15}\)
C. \(\frac{3}{16}\)
D. \(\frac{7}{8}\)

Question 140:

• JAMB 1991

3% of a family's income is spent on electricity, 59% on food, 20% on transport, 11% on education and 7% on extended family. The angles subtended at the centre of the pie chart under education and food are respectively

A. 76.8^o and 25.2^o
B. 10.8^o and 224.6^o
C. 112.4^o and 72.0^o
D. 39.6^o and 212.4^o