Question 750301
Jerry takes 6 hours to ride a bicycle 30 miles against the wind. He takes two hours to return with the wind. Find Jerry's average riding speed in still air and the average speed of the wind.
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I assume you mean 30 miles instead of 30 minutes
let x= Jerry's average riding speed in still air
let c= Average speed of the wind
x+c=speed with the wind
x-c=speed against the wind
travel time=distance/speed
30/(x-c)=6
30/(x+c)=2
..
6x-6c=30
2x+2c=30
..
6x-6c=30
6x+6c=90
add
12x=120
x=10
2c=30-2x
2c=30-20=10
c=5
Jerry's average riding speed in still air=10 mph
Average speed of the wind=5 mph