### The average mark of student in 4 subjects is 75. If the student obtained 80 marks in the fifth subject, then the new average is-

A. 72.5 B. 76 C. 77 D. 77.5 Answer: Option B

### Solution(By Apex Team)

$\begin{array}{l}\text{Sum of marks in 4 subjects}\\ \text{= 75 × 4}\\ \text{= 300}\\ \text{Sum of marks in 5 subjects}\\ \text{= 300 + 80}\\ \text{= 380}\\ \text{∴ New average}\\ =\Large\frac{380}{5}\\ =76\end{array}$

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