Question

A water filter takes 40mins to filter 20 liters of water.Another filter of same specifications takes 30mins to filter the same amount of water.If both the filters are used at the same time ,then howlong will it take them to filter 70 litrs of water.

Answer 1

Answer:

60 minutes

Explanation:

filter A filters 20/40 liters in 1 minute

filter B filters 20/30 liters in 1 minute

both  filters  filter (  1/2 + 2/3)  liters in 1 minute

both  filters  filter (  7/6)  liters in 1 minute

there fore

both  filters  filter (1)  liters in 6/7 minutes

both  filters  filter (70)  liters in 6/7 x 70 minutes = 60 minutes