A boy rides his bicycle 10 km at an average speed of 12 km/hr and again travels 12 km at an average speed of 10 km//hr. His average speed for the entire trip is approximately:
A. 10.4 km/hr
B. 10.8 km/hr
C. 11 km/hr
D. 12.2 km/hr
Answer: Option B
Solution(By Examveda Team)
Total distance travelled := (10 + 12) km
= 22 km
Total time taken :
$$\eqalign{ & = \left( {\frac{{10}}{{12}} + \frac{{12}}{{10}}} \right){\text{ hrs}} \cr & = \frac{{61}}{{30}}{\text{ hrs}} \cr} $$
∴ Average speed :
$$\eqalign{ & = \left( {22 \times \frac{{30}}{{61}}} \right){\text{ km/hr}} \cr & = 10.8{\text{ km/hr}} \cr} $$
Related Questions on Speed Time and Distance
A. 48 min.
B. 60 min.
C. 42 min.
D. 62 min.
E. 66 min.
A. 262.4 km
B. 260 km
C. 283.33 km
D. 275 km
E. None of these
A. 4 hours
B. 4 hours 30 min.
C. 4 hours 45 min.
D. 5 hours
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