Hello from MrBillDoesMath!
Answer:
The average is increased by 5
Discussion:
Let x be one number and y the other number.
Average of x,y = (1/2) ( x + y)
if, say, x is increased by 10 then the average of the numbers is
( ( x+ 10) + y) /2
= (x+y)/2 + 10/2 => (x+y)/2 is the average of the original numbers
= (x+y)/2 + 5
So the average is increased by 5
Thank you,
MrB