Waec Further Mathematics 2012 Past Questions and Answers

Question 16:

• WAEC 2012

A binary operation, \(\Delta\), is defined on the set of real numbers by \(a \Delta b = a + b + 4\). Find the identity element.

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

Question 17:

• WAEC 2012

The marks obtained by 10 students in a test are as follows: 3, 7, 6, 2, 8, 5, 9, 1, 4 and 10. Find the mean mark.

A. 4.50
B. 5.50
C. 6.50
D. 6.75

Question 18:

• WAEC 2012

The marks obtained by 10 students in a test are as follows: 3, 7, 6, 2, 8, 5, 9, 1, 4 and 10. Find the variance.

A. 8.25
B. 8.50
C. 9.00
D. 9.17

Question 19:

• WAEC 2012

If r denotes the correlation coefficient between two variables, which of the following is always true?

A. \(0 < r \leq 1\)
B. \(-1 \leq r < 1\)
C. \(-1 < r \leq 0\)
D. \(-1 \leq r \leq 1\)

Question 20:

• WAEC 2012

A stone is dropped from a height of 45m. Find the time it takes to hit the ground. \([g = 10 ms^{-2}]\)

A. 3.0 seconds
B. 4.5 seconds
C. 5.0 seconds
D. 9.0 seconds