Question

What is the ratio of the number of gray T-shirts to the number of black T-shirts?

Answer 1

First find out how many gray T-shirts there are and how many black T-shirts.

Add up the numbers in the Black column, you get 20.
Add up the numbers in the Gray column, you get 14.

Ratio of the number of gray T-shirts TO the number of black T-shirts.

The keyword here is 'to', because this is what divides the two ratios. Number of gray T-shirts is 14, and the number of black T-shirts is 20, so we have:

$\sf 14:20$

We can simplify this by dividing 2 to both numbers:

$\boxed{\sf 7:10}$