Question 21
Vendor Peter sells red and green apples, where both quantities are the same. He initially plans to sell the apples in the following manner: three red apples for 1 dollar and two green apples for 1 dollar. But to make things easier, he decided to sell them altogether and sells any five apples for 2 dollars. After selling out all his apples, he realizes that the strategy to sell the apples together earns 7 dollars less than his original plan. How many apples of each colour does Peter have at the beginning?