Question

Look at the following table below.

$$\begin{array}{cc}Classinterval& Classmark\\ 0-5& A\\ 5-10& B\\ 10-15& 12.5\\ 15-20& 17.5\end{array}$$

The value of A & B respectively are:

• A. 2, 7
• B. 3, 7
• C. 3,8
• D. 2.5, 7.5

Answer 1

The correct option is D

2.5, 7.5

Class mark for a class interval = $\frac{Upperclasslimit+Lowerclasslimit}{2}$

For first class upper class limit is 5 and lower is 0. Thus class mark for it is 2.5 using formula.

For 2^nd class upper class limit is 10 and lower limit is 5. Thus class mark for it is 7.5.