A man goes from C to D at 40 km/h and he returns from D to C at x km/h. If the average speed of the man for the whole journey is 60 km/h, then what is the value of x?
A.110
B.80
C.120✓ Correct
D.100
Explanation
Average speed for round trip = 2ab/(a+b) = 60. So 2×40×x/(40+x) = 60. Solving: 80x = 2400+60x, 20x = 2400, x = 120.
💡 Practice unlimited SSC MTS PYQs + AI-tracked progress on each topic. Sign up free →