Answer:
The correct answer is 60%.
Step-by-step explanation:
We know that the store had a profit of $ 30 for the pair of shoes sold.
Now we must transform that $ 30 into a percentage.
And one of the ways in which we can calculate this percentage is with the following percentage formula:

P is the percentage we want to calculate.
The number B is the profit we have obtained, 30
And number A is the total of the product, 50
Thus:


P= 60 %
Given this information, we can say that the percentage markup is 60%.