Two motorcycles are travelling at speeds of 120km/h and 90km/h respectively.
If the faster one travels for 4 hours longer than the slower one and also goes twice as far, how far did the slow one travel?
+495 720 km
| Hour | 120kmh Motorcycle | 90 kmh motorcycle |
| 0 | 0 | 0 |
| 1 | 120 | 90 |
| 2 | 240 | 180 |
| 3 | 360 | 270 |
| 4 | 480 | 360 |
| 5 | 600 | 450 |
| 6 | 720 | 540 |
| 7 | 840 | 630 |
| 8 | 960 | 720 |
| 9 | 1080 | 810 |
| 10 | 1200 | 900 |
| 11 | 1320 | 990 |
| 12 | 1440 | 1080 |
Look at the graph. Look at hour 12. The faster motorcycle traveled twice as far the slower motorcycle had 4 hours ago.
Look at how far the slower motorcycle went at hour 8. 720 km
I hope this was useful :)
+130536 Thanks, LambLamb for that good answer......!!!!
Here's another way to figure this out.....
Let T be the total travel time - in hours - for the slower bike....so T + 4 = the total travel time - in hours- for the faster one....and we have Rate * Time = Distance.......so......twice the distance the slower one traveled = the distance the faster one traveled.......or, algebraically......
2[90T] = 120[T + 4] simplify
180T = 120T + 480 subtract 120T from both sides
60T = 480 divide both sides by 60
T = 8hrs
So....the slower bike travels ..... 90kmh(8h) = 720km
And as LambLamb pointed out.......the faster one traveled 120km/hr (12h) = 1440km
