A) 3 km/h |
B) 2 km/h |
C) 5 km/h |
D) 7.7 km/h |
B) 2 km/h |
According to the formula,
Average speed = \( \Large \frac{2AB}{A+B} \)
Here, A = 5 km/h, and B = 2 km/h
Therefore, Required average speed = \( \Large \frac{2 \times 5 \times 2}{7} = \frac{20}{7} = 2\frac{6}{7} km/h \)