A van is travelling from Town J to Town K. At 55 km/h, it will arrive five hours later than the scheduled time. At 70 km/h, it will arrive at two hours later than the scheduled time. What is the distance between Town J and Town K?
| |
Faster speed |
Slower speed |
| Speed |
70 km/h |
55 km/h |
| Time |
1 u + 2 |
1 u + 5 |
| Distance |
70 (1 u + 2) =
70 u + 140 |
55 (1 u + 5) =
55 u + 275 |
Distance covered for the faster speed or the slower speed is the same.
70 u + 140 = 55 u + 275
70 u - 55 u = 275 - 140
15 u = 135
1 u = 135 ÷ 15 = 9
Distance between Town J and Town K
= 70 u + 140
= 70 x 9 + 140
= 630 + 140
= 770 km
Answer(s): 770 km
