Start with the speeds of the cars: Car A can travel at 110mp/h. Car B can travel at a speed of (110×0.9)99mp/h. Car C can travel at a speed of (110+99)∕2=104.5mp/h. If it took car A 30 minutes, the length towards the middle of the triangle is 55 miles. Calculate how long it takes car B and car C travel 55 miles: Car B: It will take her (55/99) hours which is 33 minutes and a third. Car C: It will take her (55/104.5) hours which is approximately 31.6 minutes. Therefore, the differences in the time will be approximately 1.5 minutes.