A) \[5\]
B) \[4\]
C) \[8\]
D) \[6\]
Correct Answer: B
Solution :
Let rate upstream\[=x\]km/hr. and rate down stream\[=y\]km/hr. Then \[\frac{25}{x}+\frac{39}{y}=8\] ? (i) and \[\frac{35}{x}+\frac{52}{y}=11\] ? (ii) Multiplying (i) by 7 and (ii) by 5 and subtracting\[\frac{13}{y}\] \[=56-55\] \[\therefore \]\[y=13\] \[\therefore \](i)\[\Rightarrow \frac{25}{x}=8-3=5\] \[\therefore \]\[x=5\] \[\therefore \]Rate of flow\[=\frac{1}{2}\] \[(13-5)=4\]km/hr.You need to login to perform this action.
You will be redirected in
3 sec