SOLUTION: Mr. Petrov drove from Richmond to Cleveland on business. The distance between the cities is 470 miles. He drove for h hours at an average speed of 50 miles per hour. Then he drove

Algebra ->  Inequalities -> SOLUTION: Mr. Petrov drove from Richmond to Cleveland on business. The distance between the cities is 470 miles. He drove for h hours at an average speed of 50 miles per hour. Then he drove       Log On


   

Question 1102979: Mr. Petrov drove from Richmond to Cleveland on business. The distance between the cities is 470 miles. He drove for h hours at an average speed of 50 miles per hour. Then he drove the remaining distance in k hours. His average speed for the k hours was 40 miles per hour. Which equation could be used to represent this situation?
A. 50h+40k=470
B. 50h-40k=470
C. (50+40)(h+k)=470
D. h+k=470/(50+40)
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
i believe your solution is going to be selection A: 50h + 40k = 470

here's why.

rate * time = distance is the formula to use.

you are told that he drove for h hours at 50 miles per hour.

let d1 be the distance traveled at that rate of speed.

you are then told that he drove the remaining distance in k hours and that his average speed for the k hours was 40 miles per hour.

let d2 be the distance traveled at that rate of speed.

rate * time = distance formula becomes:

50h = d1
40k = d2

you know that d1 + d2 = 470

just replace d1 and d2 in this equation with their equivalent values of 50h and 40k and you get 50h + 40k = 470

that's selection A.