The average (arithmetic mean) of y numbers is x. If 15 is added to the set of numbers, then the average will be x - 5. What is the value of y in terms of x ?	Choose the correct choice from the following options:
A) x/6 - 6
B) x/6 - 5
C) x/7 - 5
D) x/5 - 4
E) x/5 - 6
(A1 + A2 + .. + Ay)/y = x   (A1 + A2 + .. + Ay + 15)/(y+1) = x - 5   =&gt; (xy + 15)/(y+1) = x - 5   =&gt; xy + 15 = yx -5y + x - 5   =&gt; 20 = x - 5y   =&gt; 5y = x - 20   =&gt; y = x/5 - 4   Answer - x/5 - 4
<result>D</result>
The average (arithmetic mean) of y numbers is x. If 15 is added to the set of numbers, then the average will be x - 5. What is the value of y in terms of x ?