Question

Taps X and Y can fill a tank in 30 and 40 minutes respectively.Tap Z can empty the filled tank in 60 minutes.If all the three taps are kept open for one minute each,how much time will the taps take to fill the tank?

Answer 1

Q:

Taps X and Y can fill a tank in 30 and 40 minutes respectively.Tap Z can empty the filled tank in 60 minutes.If all the three taps are kept open for one minute each,how much time will the taps take to fill the tank?

Answer: 24min 

Explanation:

Given taps X and Y can fill the tank in 30 and 40 minutes respectively. Therefore,
 
part filled by tap X in 1 minute = 1/30
 
part filled by tap Y in 1 minute = 1/40
 
Tap Z can empty the tank in 60 minutes. Therefore,
 
part emptied by tap Z in 1 minute = 1/60
 
Net part filled by Pipes X,Y,Z together in 1 minute = [1/30 +1/40 - 1/60] = 5/120 = 1/24
 
i.e., the tank can be filled in 24 minutes.

Answer 2

Answer:

x =30 minutes

y =40 minutes

z = 60 minutes(empty)

TOTAL WORK=LCM(30,40,60)=120

A WORK DONE PER MINUTE(120/30)=4

A WORK DONE PER MINUTE(120/40)=3

A WORK DONE PER MINUTE(120/60)=(-2)(BECAUSE TANK WILL EMPTY)

1 PAIR=5 IN 3 MINUTES

24 PAIR=120 IN 72 MINUTES

SO ANSWER IS 72 MINUTES

Step-by-step explanation: