A) 70 km/h
B) 60 km/h
C) 50 km/h
D) 45 km/h
E) 40 km/h
Correct Answer: B
Solution :
[b] Let speed of motorcycle for next 40 km journey be \[x\,km/h.\] Then, \[30=\frac{2\times 20\times x}{20+x}\] \[\Rightarrow \] \[3\,(20+x)=4x\] \[\Rightarrow \] \[60+3x=4x\] \[\Rightarrow \] \[4x-3x=60\] \[\Rightarrow \] \[x=60\,km/h\]You need to login to perform this action.
You will be redirected in
3 sec