Correct Answer - Option 2 : 12:30 PM
Given:
R and S started their journey towards one another at 10 a.m.
Speed of R = 3 kmph
Speed of S = 4 kmph
Distnce between them = 17.5 km
Concept used:
Relative speed = R's speed + S's speed (as they are traveling towards each other)
Speed = distance/time
Calculation:
Speed = 3 + 4 = 7 kmph
Tim when they meet = distance/speed = 17.5/7
Time = 2.5 hours from 10 am
∴ They will meet at 12 hour 30 mins.