Easy to solve this kinda puzzles:- Let’s assume, x is time taken by son and y is time taken by father to complete the distance to the factory. From , what is given, we can have the below simultaneous equations:- x/y = 20/30 = 2/3 ——– (1) y – x = 5 (as son starts 5 mins later) ———– (2) Solving 1 & 2 we get, x=10 and y=15. Thus father son will catch up, 15 minutes from when the father started i.e 10 mins from the son’s start. Also, to note, they will catch up at half the distance to the factory as the father son duo takes 30 and 20 minutes respectively to the factory.
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