Question

The average of 7 numbers is 60. the average of the first three numbers is 50, while the average of the lastthree is 70. what must be the remaining number

Answer 1

sum of all 7 numbers=60*7=420
sum of first 3 numbers= 3*50=150
sum of last 3 numbers= 3*70= 210
so the Remaining number is 420-(150+210)=60