Question

A cold water tap can fill a bath in 3min while a hot waterr tap in 5min.the drain pipe can empty in 3min 45 sec.the two taps and the drain pipe are fully opened for two min after which the drain pipe is closed. a)what fraction of the bath is filled after 2min b)how many seconds are required for the bath to be completely filled

Answer 1

Answer:

Cold water tap can fill a bath in 3 min

so , in one minute it fills = 1/3 bathtub

hot water tap can fill a bath in 4 min

so in one minute it fills = 1/4 bathtub

waste pipe can empty bathtub in 6 min

so in one minute it empty = 1/6 bathtub

all together makes work in one minute = 1/3 + 1/4 - 1/6

= 4/12 + 3/12 - 2/12

= 5 / 12

so it takes , 12/5 minutes

= 2.4 minutes

i. e. 2 minutes 24 seconds