Solution to CyberTeaser B268
The fly was airborne for 1 hour (the time that passed until the bikers met). The fly flew with the wind for 23 km more than it flew into the wind (this is the distance traveled by Josh). If we let t1 and t2 be the times during which the fly flew with the wind and into the wind, respectively, we can set up a system of equations:
t1 + t2 = 1,
We find t1 = 53/70 and t2 = 17/70. Therefore, the distance traveled by the fly is
40 × 53/70 + 30 × 17/70 = 37 4/7 km.
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