If the arithmetic mean of seventy-five numbers is calculated, it is 35. if each number is increased by 5, then mean of new numbers is :

Let the numbers are  $x1,x2,.......x75$

By Hypothesis , $\frac{x1+x2+....x75}{75}=35$ ......(i)

Mean of new numbers =  $\frac{x1+5+x2+5+.......x75+5}{75}$

$\frac{x1+x2+......x75+5*75}{75}$

$\frac{x1+x2+......x75}{75}+\frac{375}{75}=35+5=40$ By (i)