- Lett¼the time it takes to ride to the friend’s house and 1.5t¼the
time it takes to walk back.
Rate Time ¼ Distance
To friend’s house 9 t 9 t
Return home 3 (1.5t) 3(1.5t)
The distances are equal since she is making a round trip.
9 t¼ 3 ð 1 : 5 tÞ
9 t¼ 4 : 5 3 t
9 tþ 3 t¼ 4 : 5 3 tþ 3 t
12 t¼ 4 : 5
121 t
121
¼
4 : 5
12
t¼ 0 :375 hour
D¼RT
D¼ 9 0 : 375 ¼ 3 :375 miles
- Lett¼the time the person on the motorcycle takes to overtake the
person on the bicycle andtþ 1 ¼the time the person on the bicycle
rides.
Rate Time ¼ Distance
Bicycle 10 tþ 1 10(tþ1)
Motorcycle 30 t 30 t
The distances are equal.
30 t¼ 10 ðtþ 1 Þ
30 t¼ 10 tþ 10
30 t 10 t¼ 10 t 10 tþ 10
20 t¼ 10
201 t
201
¼
10
20
t¼ 0 :5 hour
LESSON 13 Solving Distance Problems 139