Question

6 taps take 15 minutes to fill up the water tank. how many minutes will it take to fill up the tank if only four taps are working.

Answer 1

if 6 taps are filling it in 15 mins
then 1 tap will in 15/6
if there will be 4 taps then the time taken = (15/6)*4
                                                                 = 5*2/1
                                                                 = 10 mins
                                                                        

Answer 2

15/6*4=15/3*2=30/3=10minutes