Question

Average of five numbers is 20. If each number is multiplied by 3, what will be the new average?

Answer 1

here are 5 numbers.

{(x-2)+(x-1)+x+(x+1)+(x+2)}=5×20

x+x+x+x+x-2+2–1+1=5×20

5x/5=(5×20)/

x=20

x-2=18

x-1=19

x+1=21

x+2=22

18+19+20+21+22=100

100/5=20

Now double each number.

36+38+40+42+44=x

80+38+40+42=x

80+80+40=200

200/5=40