It takes 10 hours to fill a pool with the inlet pipe. it can be emptied in 15 hours with the outlet pipe. if the pool is 2/3 full to begin with, how long will it take to fill it from there if both pipes are open?

answer: the answer is one

step-by-step explanation:

pemdas, in this situation there is no parenthesis or exponents so you go to multiplication, 1x1=1, then division 1/1= 1 then addition 1+1=2 then subtraction 2-1=1