Answer:
Step-by-step explanation:
Step 1
Data of Roger,
Roger runs 1 mile in 21 minutes.
So, Rate by which Roger is running = 1/21 mile/ minute.
Let, Roger runs for x minutes.
So, total distance ran by Roger = rate * time = x/21 mile.
Step 2
Data of Jeff,
Jeff runs 1 mile in 18 minutes.
So, Rate by which Jeff is running = 1/18 mile/ minute.
As Jeff gives Roger a 1 minute head start, so Jeff will run for (x-1) minutes.
So, total distance ran by Jeff = rate * time = (x-1)/18 mile.
Step 3
Equation:
distance = distance
x/21 = (x-1)/18
18x = 21x-21
3x = 21
x = 7 minutes (Roger time)
Roger will run rt = (1/21)7= 1/3 mile
x-1 = 6 minutes (Jeff time)
Jeff will run rt = (1/18)6 = 1/3 mile