Correct Answer - Option 4 : 25

Let the average upto 11th innings be x

So, the total number of runs after 11 innings = 11 × x = 11x

After 80 runs are scored in the 12th innings, the new total runs = 11x + 80

Also, the new average = x + 5

From the given conditions,

12(x + 5) = 11x + 80

⇒ 12x + 60 = 11x + 80

⇒ x = 20

**∴ The average after the 12th innings = 20 + 5 = 25 runs**