Question

Find the number that makes the ratio equivalent to 1:3. 7:

Answer 1

The number that makes this ratio equivalent is 21 because 7 x 3 = 21

Answer 2

1:3

For each one there is of one item, there is three of another.

Therefore, the answer is 7:21
For every single item, there is three, so 7 times 3. The answer is 21, which completes the ratio.