Question: In a grocery store, four apples cost $5.20, and three oranges cost $3.30. How much will Clyde pay for 5 apples and 5 oranges?
Solve it. 
Answer: 
Each apple costs $5.20/4 = $1.30.
Each orange cost $3.30/3 = $1.10.
So 5 apples cost $1.30 x 5 = $6.50.
And 5 oranges cost $1.10 x 5 = $5.50.
Thus, Clyde will pay $6.50 + $5.50 = $12 for 5 apples and 5 oranges.