### Core Concept The problem involves calculating time taken for different distances at different speeds. The key formula used is:
Time=SpeedDistance ### Step-by-Step Solution
Let walking speed be
v.
Running speed is
1.4v (40% more than walking speed).
Distance from A to B:
d1.
Distance from B to C:
d2.
Time to walk from B to C: 210 minutes.
Time to run from B to A: 210 minutes.
Walking from B to C:
210=vd2 ⇒
d2=210v.
Running from B to A:
210=1.4vd1 ⇒
d1=210×1.4v=294v.
4
Calculate Required Times:
Walking from A to B:
vd1=v294v=294 minutes.
Running from B to C:
1.4vd2=1.4v210v=150 minutes.
294+150=444 minutes.
### 30-Second Shortcut Recognize that the time taken to cover each segment inversely relates to speed. Since running is 1.4 times faster, the time saved on the return trip can be calculated proportionally.
### Final Answer Correct Answer: 444