Question

A person travels in a car from his village to at own at a speed of 50 kms/hr for four hours There he spends an hour moving about 20 kms. He then returns to his village at a speed 40 kms/hr, His average speed over the whole journey (in kms/hr) is

• A. 44
• B. 42
• C. 44$\frac{4}{9}$
• D. 46$\frac{2}{3}$

Answer 1

The correct option is B 42

Distance = speed $\times$ time
Distance covered in car = 50 $\times$ 4 = 200 km
He move for 1hr = 20km
Time take while retraining from town to village time $=\frac{Distance}{Speed}=\frac{200}{40}=5hr$
Total journey = 200 + 200 + 20
Total time taken = 4 + 1 + 5 = 10
Average speed $=\frac{420}{10}=42km/hr$