The time it takes to cover the distance between two cities by car is inversely proportional to the speed of the car. The trip takes 3 hours for a car moving at 68 mph. What is the speed of a car that makes the trip in 12 hours?
2007-07-23 09:20:17 · 3 answers · asked by Aimee R 1 in Science & Mathematics ➔ Mathematics
well 3hours at 68 mph=204 miles
so 204miles/12hour=17miles per hour
2007-07-23 09:23:56 · answer #1 · answered by leo 6 · 0⤊ 0⤋
t ~ 1/v
d = 68 * 3 = 204 miles
v = 204/12 = 17 mph
2007-07-23 16:25:35 · answer #2 · answered by gebobs 6 · 0⤊ 0⤋
hrs.......mph
3 ..........68
12..........x
(3 * 68) / 12
it is an inverse rule of 3. while one goes up the other one goes down, so you dont multiplie in an x manner, but just straight on and divide on whats below to put the x to one side. the answer is 17 mph
2007-07-23 16:32:07 · answer #3 · answered by Eltohn 2 · 0⤊ 0⤋