A) 7 minutes
B) 6 minutes
C) 8 minutes
D) 9 minutes
Correct Answer: C
Solution :
(c): Let after 't' minutes 'B' be closed For first 't' minutes Part filled\[=t*\left[ \frac{1}{24}+\frac{1}{32} \right]\] \[=t*\frac{7}{96}\] Part left \[=\left( 1-\frac{7t}{96} \right)\] 'A' filled 1/24 part in 1 min \[\Rightarrow \]A fills \[=\left( 1-\frac{7t}{96} \right)\] part in 24\[=\left( 1-\frac{7t}{96} \right)\] min Now, \[t+24\text{ }\left( 1-\frac{7t}{96} \right)=18\] \[\Rightarrow t+24-\frac{7t}{4}=8\] \[\Rightarrow 6=\frac{3t}{4}\Rightarrow t=18\].You need to login to perform this action.
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