3 Dave can drive from Abdet to Bentall by two routes. The old route goes in roughly a straight line while the new faster route is 26% longer. Dave's average speed on the new faster route is 40% higher than his average speed on the old route. (a) By what percentage is Dave's journey time reduced by taking the new route compared to the old? [2]

Sagot :

Answer:

10 % of the total time will be saved on the new route with the new speed.

Step-by-step explanation:

Let x miles  be the old route. Then the new route would be 1.26 x miles

Let y be the speed on the old route . Then the speed on the new route would be 1.4 y .

And let t be the time on the old route

Speed = Distance / Time

or

Time = Distance / Speed

t= x/y

     Time for the new route   = 1.26x/ 1.4y= 0.9 t

0.9 t means 90% of the old time will be required to cover 1.26x  miles with 1.4 y speed.

And 10 % of the total time will be saved on the new route with the new speed.