(b) Let the time taken by Ram to finish the race = t min
Case I Ram gives Shyam a start of 200 m and beats him by 30 s, i.e.,
21​ min.
∴ Speed of Ram =
t2000​and, speed of Shyam =
t+21​1800​ Case II Here, Ram gives Shyam a start of 3 min and losses to Shyam by 1000 m.
∴ Time taken by Shyam - Time taken by Ram = 3 m
t+21​1800​2000​−t2000​1000​ = 3
⇒
2t+11800×2​2000​−2t​ = 3
⇒
1800×22000×(2t+1)​−2t​ = 3
⇒
95​(2t+1)−2t​= 3
⇒
1810(2t+1)−9t​ = 3
⇒ 20t + 10 - 9t = 18 x 3
⇒ 11t = 54 - 10
∴ t =
1044​ = 4min
So, time taken by Ram to finish the race is 4 min.
Again, speed of Shyam
=
t+21​1800​ ⇒
4+21​1800​ =
8+11800​×2 = 400 m/min
So, to cover 2000 m Shyam will take 5 min.