Problema Solution
After 20 minutes into a cross country race, Teck Seng has run 5/8 of the route while Jack has covered only 3/8 of the distance. Teck Seng runs at the same average speed throughout the race and Jack's average speed is
60 m/min slower than Teck Seng's.
a) Find the total distance of the cross country race.
b) If Jack wants to finish the race at the same time as Teck Seng, by how much should he increase his average speed for the remaining part of the race? (Express your answer in m/min)
Answer provided by our tutors
let total distance=x
teck seng cover=5/8x
jack cover=3/8x
speed of teck seng=vm/min
speed of jack=v-60m/min
time same
5x/8v=3x/8(v-60)
16v=2400
v=150m/min
v=s/t
t=20min
s=20v
5x/8=20*150
x=4800m
2)
for reach same time jack have to increase his speed 60m/min