Sachin Tendulkar has a certain average for 11 innings. In the 12th innings he scores 120 runs and thereby increases his average by 5 runs. His new average is :

Answer: Option C

Let the average of '11' innings is = x
According to the question,
$$\frac{11x+120}{12}=x+5$$
11x + 120 = 12x + 60
x = 60
∴ His new average
= 60 + 5
= 65