A Kangaroo wants to cross a 3 lane highway, all cars going in same direction. All lanes are 7 feet wide.
In lane A a car passes every 4 seconds
In lane B a car passes every 3 seconds
In lane C a car passes every Prime Number seconds (2,3,5,7,11,13,17,19,23 etc seconds)
The Kangaroo can only do the following:
Jump forward exactly 5 feet in 3 seconds. Once he jumps cars cannot hit him. So it is instantaneous.
Jump backwards exactly 2 feet in 3 seconds
He can ONLY go in straightline perpandicular to the lane direction. No fractional seconds in this puzzle. The (zero) time starts when all cars pass simultaneously in front of him so the next car in lane A will pass in 4 seconds, one in lane B will pass in 3 seconds and one in lane C will pass in 2 seconds. The next car in lane C will pass at 3 second mark the next one at 5 second mark, the next one at 7 sec mark and so on.
Mr. Kangaroo needs to get across the 3 lanes in less than 25 seconds.