The mean of `15` numbers is `15.` If the two numbers `18 and 12` are excluded, then find the mean of remaining numbers

The mean of 17 numbers is 12. If two numbers 9 and 15 are removed, then what will be the mean of remaining number?

The mean of a set of seven numbers is 81. If one of the number is discarded, then the mean of the remaining numbers is 78. The value of discarded number is

The mean of six numbers is 23. If one of the numbers is excluded , the mean of the remaining numbers is 20. find the excluded number.

The mean of a set of eight numbers is 63. If one of the numbers is discarded, the mean of the remaining numbers is 58. The value of discarded number is

The average of 15 numbers is 56. The average of first 8 numbers is 54.4 and that of last 8 numbers is 56.6. If 8^(th) number is excluded then what is the average of the remaining numbers? (correct to one decimal place)

The arithmetic of 12 observations is 15. If two observations 20 and 25 are removed then the arithmetic mean of remaining observations is