Answer:
The number of apples did Lisa eat is 8
Step-by-step explanation:
Given as :
Total number of apple to eat in contest between Charles and Lisa = 18
Let The number of apples ate by Charles = x
So, The number of apples ate by Lisa = x + 2
Now,
Total number of apples to eat in contest between Charles and Lisa = 18
Or, x + ( x + 2 ) = 18
Or, ( x + x ) + 2 = 18
Or, 2 x = 18 - 2 = 16
∴ x = 
I.e x = 8
So , The number of apples ate by Lisa = x = 8
The number of apples ate by Lisa = x + 2 = 8 + 2 = 10
Hence The number of apples did Lisa eat is 8 Answer