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:
[tex]\sf 14:20[/tex]
We can simplify this by dividing 2 to both numbers:
[tex]\boxed{\sf 7:10}[/tex]
