18 hrs
13 hrs
20 hrs
23 hrs
C. 20 hrs
Part filled by A in 1 hour = (1/36);
Part filled by B in 1 hour = (1/45);
Part filled by (A + B) In 1 hour =(1/36)+(1/45)=(9/180)=(1/20)
Hence, both the pipes together will fill the tank in 20 hours.
100 hrs
122 hrs
177 hrs
112 hrs
10 min
20 min
40 min
50 min
18 hrs
13 hrs
20 hrs
23 hrs
20 hrs
23 hrs
30 hrs
21 hrs
39 min
40 min
50 min
45min
7 hrs
7 hrs 30 min
5 hrs
5 hrs 30 min