Question

the average of a list of 6 numbers is 20. if we remove one of the numbers the average of the remaining numbers is 15. what is the number that was removed

Answer 1

Solution,

Average of 6 numbers=20

Total of 6 numbers=6 x 20=120

When one number is removed,

the average of 5 numbers=15

the total of 5 numbers=15x5=75

Now,

the number that was removed=120-75=45

Hence, 45 was the number.

Explanation: