Respuesta :
Answer:
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