It's a 16% increase
The first way you could do it
First, you have to subtract 58-50 because you need to find how much more red loafers they sold in March than in February.
58-50=8
Then you need to divide 8/50 to get 0.16, which is also 16% increase.
The other way you could've done it
You would do the same first step as you woulf in the first way, but you could try finding what other fraction that has 100 as the denominator and is equal to 8/50.
[tex] \frac{8}{50} = \frac{x}{100} \\ 50 \times 2 = 100 \\ 8 \times 2 = 16 \\ \frac{16}{100} = 16\%[/tex]