The speeds of two buses are in the ratio 5 : 3. If the first bus covers 400 km in 8 hours (50 km/h), find the speed of the second bus (in km/h).

Introduction / Context:
Again, ratios scale real values. With the first bus speed known from distance/time, use the 5 : 3 ratio to compute the second bus speed.

Given Data / Assumptions:

• Speed ratio (Bus1 : Bus2) = 5 : 3.
• Bus1 speed = 400/8 = 50 km/h.

Concept / Approach:
Each “part” equals 50/5 = 10 km/h. Thus, Bus2 speed is 3 parts = 30 km/h.

Step-by-Step Solution:

Verification / Alternative check:
50 : 30 reduces to 5 : 3—consistent with the ratio.

Why Other Options Are Wrong:
15, 27, 37, 25 km/h do not maintain the correct proportionality with Bus1 = 50 km/h.

Common Pitfalls:
Applying the ratio inversely or mixing which bus corresponds to 5 or 3 parts.

Final Answer:
30 km/h