Two bicyclists ride in opposite directions. The speed of the second bicyclist is 5 miles per hour faster than the first. After 2 hours they are 70 miles apart. Find their rates. A. 15 mi/h; 20 mi/h B. 32.5 mi/h; 37.5 mi/h C. 20 mi/h; 25 mi/h
Question
Answer:
A. 15 mi/h; 20 mi/hr
Explanation:
Let y mi/h be the speed of first bicyclist. According to the problem, (y + 5) mi/h be the speed of second bicyclist.
After 2 hours,
Distance covered by first bicyclist, d₁ = 2y
Distance covered by second bicyclist, d₂ = 2(y+5)
Since, the two bicyclist are moving in opposite directions. Thus sum of their
distance is equal to the total distance they are apart, that is,
d₁ + d₂ = 70
2y + 2(y+5) = 70
4y + 10 = 70
4y = 60
y = 60/4 = 15 mi/h
Speed of first bicyclist = y = 15 mi/h
Speed of second bicyclist = y + 5 = 15 + 5 = 20 mi/h
Answer:
A. 15 mi/h; 20 mi/hr
Explanation: