Question 997994
Pedros speed = x mph
Carlos speed = 3x

Distance = 45 miles

Carlos time = 45/3x

Pedro time 45/x

Condition 
Carlos time +3 =  Pedro.s time

45/3x + 3=  (45/x)

(45/x) - (45/3x) = 3

(135-45)/3x= 3

90 =9x

x= 10 

Pedro's speed = 10 mph
Carlo's speed = 30 mph