Question

A fish tank can be filled in 10 minutes using both pumps A and B simultaneously however pump B can pump water in OR out at the same rate if pump B is inadvertently run in reverse

Answer 1

Answer:

A fish tank can be filled in 10 minutes using both pumps A and B simultaneously however pump B can pump water in OR out at the same rate if pump B is inadvertently run in reverse then it take 30 mins

Time taken by A alone = 15 min

Step-by-step explanation:

complete question is if B run reverse then time taken = 30 min

Let Say A alone take  = A mins

Then tank filled by A in 1 min =  1/A

Tank filled by A & B together in 1 min = 1/10

tank filled by B alone in 1 Min = 1/10 - 1/A  =  (A-10)/10A

if B id reversed then both takes 30 min

means tank filled in 1 min = 1/10

1/A - (A-10)/10A = 1/30

multiplying by 30A both sides

=> 30 - (3A-30) = A

=>  60 = 4A

=> A = 15

A alone will take 15Mins