SOLUTION: A man bought new car from showroom and against advice, drives off at a fixed high speed for 3 hrs.Although he was warned, the engine goes "blooey" and he is forced to drive the la

Algebra ->  Average -> SOLUTION: A man bought new car from showroom and against advice, drives off at a fixed high speed for 3 hrs.Although he was warned, the engine goes "blooey" and he is forced to drive the la      Log On


   



Question 1038021: A man bought new car from showroom and against advice, drives off at a fixed high speed for 3 hrs.Although he was warned, the engine goes "blooey" and he is forced to drive the last hour of his trip home at 1/5 his initial speed.
If he lives 512 km from showroom, how fast was he going when he blew the engine?

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Speed is x mph, and in 3 hours, he went 3x miles. In the last hour he went (1/5)x miles
He drove 3x+(x/5) =512 km
(16/5)x=512
x=512*5/16=160 km/h ANSWER
In 3 hours he made 480 km. The last hour he drove 1/5 of that speed, or 32 km.