Question

Joni's jar of 10 marbles contains 2 red, 3 blue, and 5 yellow marbles. How many red marbles would Joni need to add to the jar, so that 1/3 of the marbles are red?

Answer 1

2 more red marbles would need to be added, so there are 4 red, 3 blue, and 5 yellow. 4/12 are red, and that reduces to the desired ratio of 1/3 (: