A) 36 min
B) 32 min
C) 28 min
D) 40 min.
Correct Answer: A
Solution :
[a] Diameter of three piped say A, B, C are in the Ratio \[1:\frac{4}{3}:2\] The ratio of flow can in the ratio \[{{1}^{2}}:{{\left( \frac{4}{3} \right)}^{2}}:{{2}^{2}}\] \[=1:\frac{16}{9}:4\] Time taken by each pipe separately to fill the tank \[=1:\frac{9}{16}:4\] If the pipe with diameter 2 cm takes 61 min. to fill the tank, then pipe A will take \[61\times 4\] minute and pipe B will take \[61\times 4\times \frac{9}{16}=\frac{61\times 9}{4}\,\min \] \[\therefore \] In 1 min all the 3 pipes will fill \[=\frac{1}{61}+\frac{1}{61\times 4}+\frac{4}{61\times 9}=\frac{4\times 9+9+4\times 4}{61\times 4\times 9}\] \[=\frac{1}{36}\] of the tank \[\therefore \] Time taken by all the three pipes to fill the tank = 36 min.
You need to login to perform this action.
You will be redirected in
3 sec
