This is easy once you know how these things work but it might cause some amusement to the uninitiated.
I have a daily mensa puzzle calendar and this was on it yesterday:-
Santa's elves set off to deliver presents to santa from the toy factory.
Their sleigh travels at a constant speed of 45 mph.
However one elf is late and sets off 8 minutes later at a constant speed of 60 mph.
Both follow exactly the same route.
How long will it take the lone elf to catch up with the rest?
@venda said45t = 60(t - 8/60)
This is easy once you know how these things work but it might cause some amusement to the uninitiated.
I have a daily mensa puzzle calendar and this was on it yesterday:-
Santa's elves set off to deliver presents to santa from the toy factory.
Their sleigh travels at a constant speed of 45 mph.
However one elf is late and sets off 8 minutes later at a constant speed of 60 m ...[text shortened]...
Both follow exactly the same route.
How long will it take the lone elf to catch up with the rest?
8 = 15t
t = 8/15 hours = 32 minutes total time
2nd elf takes 24 minutes once he starts.
@bigdoggproblem saidCorrect.There's more than one way to tackle it but your way is probably the simplest.
45t = 60(t - 8/60)
8 = 15t
t = 8/15 hours = 32 minutes total time
2nd elf takes 24 minutes once he starts.
I did it with ratio's the times being in the ratio of 3:4, therefore
4x =3(x +8)
x = 24