2019 · Q74
A person carries Rs. 500 and wants to buy apples and oranges out of it. If the cost of one apple is Rs. 5 and the cost of one orange is Rs. 7, then what is the number of ways in which the person can buy both apples and oranges using the total amount?
Elementary MathematicsNumber System
- A10
- B14
- C15
- D17
Explanation
5a+7o = 500 with a,o >= 1 gives o a multiple of 5: o = 5k, a = 100-7k >= 1, so k = 1..14, i.e. 14 ways.