Step 1: When Anil finishes 1500 m, Bakul runs 1500−150=1350 m.
Thus, vBvA=13501500=910.
Step 2: When Bakul finishes 1500 m, Charles runs 1500−75=1425 m.
Thus, vCvB=14251500=1920.
Step 3: vCvA=910×1920=171200.
So, vAvC=200171.
Step 4: When Anil runs 1500 m, Charles runs 1500×200171=1282.5 m.
Anil beats Charles by 1500−1282.5=217.5 m.
a) 217.50 m
Step 1: In 500 m race, A beats B by 50 m, so when A runs 500 m, B runs 450 m.
vBvA=450500=910.
Step 2: In 600 m race, B beats C by 60 m, so when B runs 600 m, C runs 540 m.
vCvB=540600=910.
Step 3: vCvA=910×910=81100.
vAvC=10081.
Step 4: In 400 m race, when A runs 400 m, C runs 400×10081=324 m.
A beats C by 400−324=76 m.
c) 76
Step 1: Speed of A: vA=25250=10 m/s.
Speed of B: vB=30250≈8.333 m/s.
Step 2: In 1000 m race for dead heat, let start given to B be x m.
B runs 1000−x m in time A runs 1000 m.
t=101000=100 s.
Step 3: vB1000−x=100.
1000−x=100×30250=100×325≈833.333.
x=1000−833.333=166.667 m.
c) 166.67 m
Step 1: A beats B by 20 m in 100 m, so when A runs 100 m, B runs 80 m.
vBvA=80100=45.
Step 2: B beats C by 5 m in 100 m, so when B runs 100 m, C runs 95 m.
vCvB=95100=1920.
Step 3: vCvA=45×1920=1925.
vAvC=2519.
Step 4: When A runs 100 m, C runs 100×2519=76 m.
A beats C by 100−76=24 m.
d) 24 m
Step 1: A beats B by 10 m in 100 m, so when A runs 100 m, B runs 90 m.
vBvA=90100=910.
Step 2: B beats C by 10 m in 100 m, so when B runs 100 m, C runs 90 m.
vCvB=90100=910.
Step 3: vCvA=910×910=81100.
vAvC=10081.
Step 4: When A runs 100 m, C runs 100×10081=81 m.
A beats C by 100−81=19 m.
a) 19 m
Step 1: A beats B by 100 m in 1500 m, so when A runs 1500 m, B runs 1400 m.
vBvA=14001500=1415.
Step 2: B beats C by 150 m in 1500 m, so when B runs 1500 m, C runs 1350 m.
vCvB=13501500=910.
Step 3: vCvA=1415×910=2125.
vAvC=2521.
Step 4: When A runs 1500 m, C runs 1500×2521=1260 m.
A beats C by 1500−1260=240 m.
d) 240
Step 1: Race is 5 km, T gets 500 m = 0.5 km head start.
T runs 4.5 km at 13.5 km/h.
Time t=13.54.5=31 h.
Step 2: S runs 5 km in t.
vS=1/35=15 km/h.
a) 15 km/h
Step 1: Pankaj's time for 140 m: tP=2.5140=56 s.
Step 2: Arun gets 20 m start, runs 120 m.
Pankaj beats by 4 s, so Arun's time for 120 m is 56+4=60 s.
Step 3: Arun's speed vA=60120=2 m/s.
c) 2 m/s
Step 1: A's time for 400 m: tA=16400=25 s.
Step 2: B gets 15 m start, runs 385 m.
A beats by 10 s, so B's time for 385 m is 25+10=35 s.
Step 3: B's speed vB=35385=11 m/s.
a) 11 m/sec
Step 1: Q's head start in 2 s at 2 m/s: 2×2=4 m.
Step 2: Q runs remaining 400−4=396 m at 2 m/s.
Time t=2396=198 s.
Step 3: P runs 400 m in 198 s.
a) 198 seconds