Answer:
It is 4
Step-by-step explanation: I know its four because 72 divided by 18 is four. I also know that 64 divided by 18 is 3.555 which is close to four.
So, by multiplying the exponents, you would add all of the square roots together. For example for your question you would add 1+1+4+5=11 so the answer is c to the power of 11
It will take him 120 mins as he runs 8 minute miles