The average of ten number is 7. If each number is multiplied by 10, then the average of the new set of number is-

Question: The average of ten number is 7. If each number is multiplied by 10, then the average of the new set of number is-

Solution:
let, 7 numbers are a₁, a₂, a₃,.......,a₇
so, (a₁ + a₂ + a₃+.......+a₇)/10 = 7
a₁ + a₂ + a₃+.......+a₇ = 70

If each number is multiplied by 10, Then sum = (a₁ × 10) + (a₂ × 10) + (a₃ × 10) + .... + (a₇ × 10)
= 10 (a₁ + a₂ + a₃+.......+a₇)
= 10 × 70
= 700

then average will be = 700/10
= 70