A car is travelling from Town Y to Town Z. At 60 km/h, it will arrive four hours later than the scheduled time. At 80 km/h, it will arrive at two hours later than the scheduled time. What is the distance between Town Y and Town Z?
| |
Faster speed |
Slower speed |
| Speed |
80 km/h |
60 km/h |
| Time |
1 u + 2 |
1 u + 4 |
| Distance |
80 (1 u + 2) =
80 u + 160 |
60 (1 u + 4) =
60 u + 240 |
Distance covered for the faster speed or the slower speed is the same.
80 u + 160 = 60 u + 240
80 u - 60 u = 240 - 160
20 u = 80
1 u = 80 ÷ 20 = 4
Distance between Town Y and Town Z
= 80 u + 160
= 80 x 4 + 160
= 320 + 160
= 480 km
Answer(s): 480 km
