First tap fills `1/18` of the cistern in 1 minute Second tap `1/24` fills of the cistern in 1 minute. First tap is turned off and the tank is filled in 12 mts. `1/24xx12 = 1/2` of the tank is filled by the second tap in 12 minutes. `1/2` of the tank is filled by the 1st tap in=`18/1xx1/2 = 9mts.` Alternate Method: I II Time 18 24 LCM 72 units Eff 4 : 3 As 1st pipes is closed so 2nd pipes is for whole time , Hence 2nd pipe will finish = 3`xx` 12=36 units So remaining = 72 - 36 = 36 units which is done by Ist, Hence 1st tap worked for = 36/4 = 9 minutes
20.5, 30, 40.5, 53, 64.5, 78
15, 34, 13, 32, 11, 28
72, 36, 54, 135, 470.5, 2126.25
125, 142, 199, 320, 489, 778
15, 30, 30, 20, 10, 8
16, 10, 12, 20, 48, 107
153, 154, 310, 913, 3736, 18685
96, 100, 86, 108, 80, 116
324, 385, 460, 549, 651, 769
11 110 978 6824 34103 102290
