Question

There is a list of seven numbers. The average of the first four numbers is 5, and the average of the last four numbers is 8. If the average of all seven numbers is 6 4/7 , find the number common to both sets of four numbers.

Answer 1

Number common to both sides=6

Explanation:

Average of first four numbers=5

4*5=20

Average of the last four numbers=8

4*8=32

Average of all seven numbers=6 4/7

7*6 4/7

Find the number common to both sets of four numbers

Solution

4*5=20

4*8=32

32+20=52

7 * 6 4/7

=7*46/7

=46

Number common to both sides=52-46

=6