City B and City C are 339 km apart. At 2.53 p.m., Zeph is travelling at a uniform speed left City B for City C while Cole set off from City C to City B along the same road at a uniform speed, which was 11 km/h slower than that of Zeph. The two met at 5.53 p.m.
- Find the speed of Zeph.
- If Cole continued to travel at the same speed, how long would it take for him to reach his destination after the two met? Express your answer in mixed number.
(a)
Time taken for Zeph and Cole to travel from 2.53 p.m. to 5.53 p.m. = 3 h
Average speed of Zeph and Cole
= 339 ÷ 3
= 113 km/h
Zeph's speed
= (113 + 11) ÷ 2
= 124 ÷ 2
= 62 km/h
(b)
Cole's speed
= 62 - 11
= 51 km/h
Distance that Cole travelled in 3 h
= 3 x 51
= 153 km
Remaining distance that Cole needed to travel
= 339 - 153
= 186 km
Time that Cole needed to reach his destination after the two met
= 186 ÷ 51
= 3
3351 = 3
1117 h
Answer(s): (a) 62 km/h; (b) 3
1117 h