Question

The average of 3numbers is 10 if the sum of the numbersis 9 what is the third number​

Answer 1

Avg of 7 numbers = 9

Total of 7 numbers will be = 9 * 7 = 63

Avg of 3 of them is = 5

Total of those 3 will be = 3 * 5 = 15

Therefore the total of other 4 = 63 - 15 = 48

Ergo , avg of them = 48 / 4 = 12

Answer is 12

hope this helps!