Question

The ratio of red to blue marbles in a bag is 3 to 4. If there are 21 red marbles in the bag, how many marbles are in the bag total

Answer 1

49 marbles in total

Explanation:

the 3 part of the ratio relates to 21 red marbles

divide 21 by 3 to find the value of 1 part of the ratio

21 ÷ 3 = 7 ← value of 1 part of the ratio, then

4 parts = 4 × 7 = 28 ← number of blue marbles

Total = red + blue = 21 + 28 = 49