consider the motion when Jim travels by bicycle
D = total distance to be traveled for the trip = 153 mile
v = speed of riding = 42 mph
t = time taken to complete the trip by bicycle = ?
using the equation
t = D/ v
inserting the values
t = 153/42
t = 3.64 h
while walking and riding :
T = total time taken to complete the trip by walking and riding = 5 hours
t ' = time of walking = T - t = 5 - 3.64 = 1.36 hours
v' = speed of walking = 4 mph
d' = distance traveled by walking = ?
distance traveled by walking is given as
d' = v' t'
d' = 4 x 1.36
d' = 5.44 miles
d = distance traveled by bicycle = D - d' = 153 - 5.44 = 147.56 miles
v = speed of riding = 42 mph
t = time spent on the bicycle = ?
time spent on the bicycle is given as
t = d/v
t = 147.56/42
t = 3.51 hours