Question

"A pump can fill a tank in 3 hours. A more powerful pump can fill the same tank in 2 hours. How long would it take to fill the tank with both pumps working?" Is my answer correct or incorrect? 1/3+1/2=3+2/3*2 5/15=15/515/5=3hrs

Answer 1

A pump can fill a tank in 3 hours. A more powerful pump can fill the same tank in 2 hours. How long would it take to fill the tank with both pumps working?" Is my answer correct or incorrect?

we have that

fisrt pump ------> fill a tank in 3 hours

that means

100% -----> 3 hours

1 hour ------> 33.33%

second pump

fill the same tank in 2 hours

100% -----> 2 hours

1 hour -----> 50 %

therefore

with both pumps working

1 hour ------> (33.33%+50%)=83.33%

applying proportion

1/83.33=x/100

x=100/83.33

x=1.2 hours

your answer is not correct

because the total time must be less than 2 hours (time of the second pump)