Question

The mean of 20 numbers is 40 . If 8 is subtracted from every number and then

multiplied by positive quantity k we get new mean as 64 . Find k ​

Answer 1

New mean will be

$\frac{20 \times 40 - 20 \times 8}{20}$

$= \frac{640}{20}$

$= 32(new \: mean)$

Now if we multiply every number by 2 then we get an other mean 64.

Answer 2

Your Answer is 20 + 40 - 64 = 4

hope it helps you