Andy started driving from City C towards City D at 13 40 at an average speed of 60 km/h. Tim began driving from City C towards City D at 15 30 at an average speed of 110 km/h.
- At what time did Tim pass Andy on the road?
- 1110 hours after passing Andy, Tim reached City D. At what time did Andy reach City D?
(a)
From 13 40 to 15 30 = 1 h 50 min
Time that Andy travelled before Tim started driving = 1 h 50 min
1 h = 60 min
1 h 50 min = 1
5060 h = 1
56 h
Distance that Andy travelled before Tim started driving
= 1
56 x 60
=
116 x 60
= 110 km
Difference between Tim's and Andy's speed
= 110 - 60
= 50 km/h
Time that Tim took to catch up with Andy
= 110 ÷ 50
= 2.2 h
= 2 h 12 min
2 h 12 min after 15 30 = 17 42
Time that Tim passed Andy on the road = 17 42
(b)
1
110 h = 1 h 6 min
Total time that Tim travelled
= 1 h 6 min + 2 h 12 min
= 3 h 18 min
3 h 18 min = 3
1860h = 3
310h
Distance between City C and City D
= 3
310 x 110
= 363 km
Time that Andy travelled from City C to City D
= 363 ÷ 60
= 6.05 h
= 6 h 3 min
6 h 3 min after 13 40 = 19 43
Time that Andy reached City D = 19 43
Answer: (a) 17 42; (b) 19 43