In this type of proportion, when one quantity is increasing, the other quantity is increasing the other            quantity too is increasing and vice versa.

Ex: a) a car covers 60km in 3 hours. How many km will it cover in 5 hours?

b) A man is paid 15000frs for 3 days. How will the man be paid for 5 days if he is working at the same rate?

Solution: a)                3hours = 60

                                       5hours = x

3x = 60 * 5 =300

 x = 300 / 3 = 100km. So, the car will cover 100km in 5 hours.

        b)                3days = 15000frs       

                            5days = x

          x = (15000 * 5) / 3 = 25000frs. So, the man will earn 25000frs in 5 days.