### The average marks in Science subject of a class of 20 students is 68. If the marks of two students were misread as 48 and 65 instead of the actual marks 72 and 61 respectively, what would be the correct average?

A. 66 B. 68.5 C. 69 D. 69.5 Answer: Option C

### Solution(By Apex Team)

$\begin{array}{l}\text{Correct sum}\\ \text{= (68 × 20 + 72 + 61 – 48 – 65)}\\ \text{= 1380}\\ \text{∴ Correct average}\\ =\Large\frac{1380}{20}\\ =69\end{array}$

A. 20
B. 21
C. 28
D. 32

A. 18
B. 20
C. 24
D. 30

A. 10 years
B. 10.5 years
C. 11 years
D. 12 years