SOLUTION: An automobile averaged 45 mph for the first part of a trip and 50 mph for the second part. If the entire trip took 4hr and covered 195 mi, for how long was the rate 45 mph?

Question 276144: An automobile averaged 45 mph for the first part of a trip and 50 mph for the second part. If the entire trip took 4hr and covered 195 mi, for how long was the rate 45 mph?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
An automobile averaged 45 mph for the first part of a trip and 50 mph for the second part.
If the entire trip took 4hr and covered 195 mi, for how long was the rate 45 mph?
:
Let x = time at 45 mph
then
(4-x) = time at 50 mph
:
Write a distance equation: dist = speed * time
:
45mph dist + 50 mph dist = 195 mi
45x + 50(4-x) = 195
:
45x + 200 - 50x = 195
:
45x - 50x = 195 - 200
:
-5x = -5
:
x = 1 hr at 45 mph
:
Check solution (3hr at 50mph)
45(1) + 50(3) = 195
RELATED QUESTIONS
An automobile averaged 40 mph for part of a trip and 50 mph for the remainder. If the... (answered by ptaylor)

Trais made a business trip of 234 miles. He averaged 54 mph for the first part of the... (answered by ankor@dixie-net.com)

Travis made a business trip of 128 miles. He averaged 56 mph for the first part of the... (answered by TimothyLamb)

Travis made a business trip of 198 miles. He averaged 52 mph for the first part of the... (answered by checkley77)

Mark made a business trip of 247.5 miles. He averaged 51 mph for the first part of... (answered by ankor@dixie-net.com)

Travis made a business trip of 198 miles. He averaged 63 mph for the first part of the... (answered by fractalier)

Travis made a business trip of 234.5 miles. He averaged 53 mph for the first part of the (answered by ankor@dixie-net.com)

Steve made a business trip of 318 miles. He averaged 54 mph for the first part of the... (answered by josmiceli)

Travis made a business trip of 305.5 miles. He averaged 49 mph for the first... (answered by jorel555)