A) 4.15 km/h
B) 4.14 km/h
C) 4.25 km/h
D) 4.41 km/h
Correct Answer: B
Solution :
Speed of A = 5 km/h \[=5\times \frac{5}{18}=\frac{25}{18}\,\,m/s\] \[\therefore \] Time Taken by A in 100 m race \[=\frac{100}{\frac{25}{18}}=\frac{1800}{25}=72\,\,s\] Given, time taken by B in \[(100-8)\]m race \[=(72+8)=80s\] \[\therefore \] Required speed of B \[=\frac{92\,\,m}{80\,\,s}=\frac{23}{20}\,\,m/s\] \[=\frac{23}{20}\times \frac{18}{5}=\frac{414}{100}\] \[=4.14\,\,km/h\]
You need to login to perform this action.
You will be redirected in
3 sec
