Answer: about 22 minutes
Explanation: its hard to explain but trust me i checked my work
The answer is c 20 percent because if divide 75 and 15 u get 5 so thats 20 percent.
That would be written as:

And the step-by-step equation would be:
→ we take the 2 to the right side of the equation and do the IO*
→we solve for 
→ final answer
*Ps - IO is not an existing term and stands for inverse operation. In this case, because when we take to 2 to the right side of the equation (the 2 is a power) it'll have to turn into a square root (because exponents and roots are inverse operations)
Hope it helped,
BioTeacher101