A) \( \Large 5\frac{9}{11} \) km/h |
B) \( \Large 11\frac{5}{9} \) km/h |
C) \( \Large 9\frac{5}{11} \) km/h |
D) \( \Large 5\frac{5}{11} \) km/h |
A) \( \Large 5\frac{9}{11} \) km/h |
Here, P = 9 km, Q = 25 km, R = 30 km
x = 3 km/h, y = 5 km/h and z = 10km/h
Therefore, Required average speed
\( \Large \frac{P + Q + R}{ \LARGE \frac{P}{x}+\frac{Q}{y}+\frac{R}{z}} \)
\( \Large \frac{9 + 25 + 30}{ \LARGE \frac{9}{3}+\frac{25}{5}+\frac{30}{10}} \)
\( \Large \frac{64}{3+5+3} = \frac{64}{11} \)
\( \Large 5\frac{9}{11} km/h \)