One hour after a hiker left camp, a biker set out to catch up. If the hiker traveled 3 miles per hour and the biker traveled 6 miles per hour faster, how long will it take for the biker to catch up with the hiker?

30 minutes after biker left

Step-by-step explanation:

Given that :

Speed of hiker = 3 mph

Speed of biker = (3 +6) = 9 mph

Present Distance of hiker when the biker set out ;

Present Distance of hiker = speed * time = (3 * 1) = 3 miles

Time taken to catchup equals :

Present distance + (distance when biker set out) = bikers distance

Let time taken = x

(3 + (3 * x)) = (9 *x)

(3 + 3x) = 9x

3 + 3x = 9x

3 = 9x - 3x

3 = 6x

x = 3/6

x = 1/2 hours

x = 30 minutes

30 minutes after biker left