Question

Welp! Tysm!!!!

Each marble bag sold by Justin's Marble Company contains 4 purple marbles for every 5 red marbles. If a bag has 20 purple marbles, how many red marbles does it contain?

Answer 1

4:5 = 20:x

Since 20/4 is 5, we know the ratio was multiplied by 5 so the bag contains 25 red marbles.