Question

Look at the following table below.

Class interval	Classmark
0 - 5	A
5 - 10	B
10 - 15	12.5
15 - 20	17.5

The value of A and B respectively are?

Options

• 3, 8

• 2, 7

• 3, 7

• 2.5, 7.5

Answer 1

2.5, 7.5

Explanation:-

Class mark for a class interval `= ("Upper class limit" + "Lower class limit")/2`

For first class upper class limit is 5 and lower is 0.

Thus class mark for it is 2.5 using formula.

For 2nd class upper class limit is 10 and lower limit is 5.

Thus class mark for it is 7.5.