A car is travelling from Town Q to Town R. At 60 km/h, it will arrive five hours later than the scheduled time. At 70 km/h, it will arrive at three hours later than the scheduled time. What is the distance between Town Q and Town R?
| |
Faster speed |
Slower speed |
| Speed |
70 km/h |
60 km/h |
| Time |
1 u + 3 |
1 u + 5 |
| Distance |
70 (1 u + 3) =
70 u + 210 |
60 (1 u + 5) =
60 u + 300 |
Distance covered for the faster speed or the slower speed is the same.
70 u + 210 = 60 u + 300
70 u - 60 u = 300 - 210
10 u = 90
1 u = 90 ÷ 10 = 9
Distance between Town Q and Town R
= 70 u + 210
= 70 x 9 + 210
= 630 + 210
= 840 km
Answer(s): 840 km
