Question

A supermarket has a certain number of watermelons and oranges. If they sell 5 watermelons and 7 oranges every day, when they run out of oranges, they would still have 433 watermelons. Or, if they sell 12 oranges and 70 watermelons a day, when the oranges have run out, they would have only 3 watermelons left. What was the initial stock of watermelons and oranges?

Answer 1

In x days they sell 7x oranges, so w = 5x+433
In y days they sell 12y oranges, so w = 70y+3
5x+433 = 70y+3
7x = 12y
Now solve as usual