Answer: 160 miles
Explanation:
Given that :
Miles ran = r ; at the speed of 5 miles per hour
Miles biked = b ; at the speed of 10 miles per hour
Total miles biked and ran = 200 miles
If she biked for twice as many hours as she ran
Let hours
Total number of miles Morgan biked
r + b = 200 - - - (1)
From speed = distance / time
Hours biked = distance / speed = b / 10
Hours ran = distance /speed = r / 5
b/ 10 = 2 (r/5)
b / 10 = 2r / 5
Cross multiply
5b = 20r
b = 4r
Substitute into (1)
r + b = 200
r + 4r = 200
5r = 200
r = 200/5
r = 40 miles
Total number of Miles biked ;
r + b = 200
40 + b = 200
b = 200 - 40
b = 160 miles