The average of 4 numbers is 100. The sum of the first 3 numbers is 350. Find the 4th number.

Answer 1

Let x be the 4th number.

The average of 4 numbers is given by the sum of all the numbers divided by 4. So, we can write:

(x + 350) / 4 = 100

Multiplying both sides by 4, we get:

x + 350 = 400

Subtracting 350 from both sides, we get:

x = 50

Therefore, the 4th number is 50.