26. TapsA and B can fiJi a bucket in 12 minutes and 15 minutes respectively. If both are opened and A is closed after 3 minutes, how much further time would it take for B to fill the bucket
A.7 nun. 45 sec. B.8 mm. 5 sec.
C.7 mm. 15 sec. D.8 mm. 15 sec.
Answer: 8 mm. 15 sec.
Explanation: Part filled in 3min = 3[(1/12) + (1/15)] = 3 * (9/60) = 9/20
Remaining part = 1 - (9/20) = 11/20
Part filled by B in 1 min = 1/15
(1/15) : (11/20) = 1 : x or x = (11/20) * 1 * (15/1) = 8 min 15 sec
Remaining part is filled by B in 8 ruin. 15 sec.
