City H and City J are 456 km apart. At 2.29 p.m., George is travelling at a uniform speed left City H for City J while Sam set off from City J to City H along the same road at a uniform speed, which was 12 km/h slower than that of George. The two met at 4.29 p.m.
- Find the speed of George.
- If Sam 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 George and Sam to travel from 2.29 p.m. to 4.29 p.m. = 2 h
Average speed of George and Sam
= 456 ÷ 2
= 228 km/h
George's speed
= (228 + 12) ÷ 2
= 240 ÷ 2
= 120 km/h
(b)
Sam's speed
= 120 - 12
= 108 km/h
Distance that Sam travelled in 2 h
= 2 x 108
= 216 km
Remaining distance that Sam needed to travel
= 456 - 216
= 240 km
Time that Sam needed to reach his destination after the two met
= 240 ÷ 108
= 2
24108 = 2
29 h
Answer(s): (a) 120 km/h; (b) 2
29 h