A) \[9\frac{2}{7}\] Min
B) \[9\frac{4}{7}\]Min
C) \[9\frac{1}{7}\] Min
D) \[9\frac{3}{7}\] Min
Correct Answer: C
Solution :
[c] Let both pipes open for x min. \[\therefore \] \[\left( \frac{1}{12}+\frac{1}{16} \right)\times x+\frac{1}{16}\times 4=1\] \[\frac{7x}{48}=\frac{3}{4}\] \[x=\frac{36}{7}\,\min \] Total time \[=4+\frac{36}{7}=\frac{64}{7}\] \[=9\frac{1}{7}\,\min \]You need to login to perform this action.
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