Jamb Mathematics 1990 Past Questions and Answers

Question 36:

• 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 37:

• 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 38:

• 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 39:

• 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 40:

• JAMB 1990

What is the equation of the quadratic function represented by the graph?

A. Y = x² + x - 2
B. Y = -x² - x + 2
C. Y = x² - x - 2
D. Y = -x² - x + 2