Question

The mean of six numbers is 20. If one number is excluded, the mean is 15. Find the value of
the excluded number.​

Answer 1

ANSWER...................,

The mean of 6 number = 20

The sum of 6 number = 6 × 20 = 120

If one number is excluded ,

Then mean of 5 number = 15

Sum of 5 number = 5 × 15 = 75

∴excluded number = 120 - 75 = 45