Another wierd math question...Lucie and Daryl's bike ride?

Lucy's rate = 8 km/hour; Daryl's = 5km/20 minutes = 15km/hour. Thus, the hypotenuse between the two bikers = 6.8 km; this is a pythagorean triplet (8.15, 17); simply multiply 6.8/17= .4; thus, Lucy was 3.2 km from where she started, she was going 8 km/hour, so she was 3.2/8(60) = 24 minutes into her journey when she made the call.