Protik rolled a dice twice and he saw that the addition of two numbers that appeared on the top face was 8. Find the probability of getting a 4 on the top face of the dice in the first throw.

A dice has 6 faces.
So there are 6 possible outcomes
Dice are rolled once AND then again.
So total possibilities = 6 x 6 = 36

The sum should be 8 of the 2 throws.
So which combination of numbers from 1 to 6 will yield us a sum of 8?
They are - (2,6); (6,2); (3,5); (5,3); (4,4)

So there are a total of 5 possibilities where the addition is 8.
But only 1 possibility where the first throw of dice is 4.

So, the Probability for the first throw to be 4 and sum to be 8 = 1/36.