Question

The ratio of the number of red marbles that Cheko had to the number of green marbles that Cheko had was 4: 3.

After he had bought 15 more green marbles,
he ratio of the number of red marbles the number of green marbles became 8 : 9.
How many marbles did Cheko have at first?

Answer 1

4m/(3m + 15) = 8/9

9(4m) = 8(3m + 15)

36m = 24m + 120

12m = 120

m = 10

Cheko had 4(10) = 40 red marbles and 3(10) = 30 green marbles at first.