Question

A fruit seller buys 700 oranges at the rate of rs 500 for 100 oranges

Answer 1

If the fruit seller buy 700 oranges, then he sells 500 for 100 oranges. Then this equation will be 700-500, after they subtracts every time, they adds. like: 700+100=800, then 800-500=300. Which you get 100 every time, which you will have 300 more oranges left everytime that you sell.