i did in the same manner bt in book there was a different ans. sol.

Rishab Soni

Its 21.
The average of 12 numbers is 9.
That means the total number is 12 X 9 = 108
if each number is multiplied by 2, the average will also be multiplied by 2.
That is the new av...

in book this is mentioned 🤔 that is why i had doubt

R

Rucha rajesh shingvekar

Correct Option: C
If each number of a set be multiplied by m, the average gets multiplied by m.
If each number of a set be increased by p, the average gets increased by p.
Here , ...

Let the sum of 12 no. be x=x1+x2+........x12
average=total no.sum of no.
⇒9=12x
sum=108
let sum of new numbers is
according to question
(x1×2+3)+(x2×2+3)+......(x12×2...