Logic/numerical puzzles

I'd like to create a thread specifically devoted to logic and numerical (not 'maths' puzzles as such, but ones requiring numerical reasoning) - the sorts of puzzles one might find in a book of brainteasers.

Please post any interesting logic or numerical puzzles you know of/can find. Thanks 🙂

I'll start the ball rolling:

How many leap years will there be between 2001 and 3001? Remember that at the turn of a new century, years are only leap years if they are multiples of 400.

Originally posted by skims
I'd like to create a thread specifically devoted to logic and numerical (not 'maths' puzzles as such, but ones requiring numerical reasoning) - the sorts of puzzles one might find in a book of brainteasers.

Please post any interesting logic or numerical puzzles you know of/can find. Thanks 🙂

I'll start the ball rolling:

How many leap years will there ...[text shortened]... r that at the turn of a new century, years are only leap years if they are multiples of 400.

242?

Originally posted by chessmasterBG
242?

correct 🙂 explain your answer?

Originally posted by skims
correct 🙂 explain your answer?

25 leap years in 100 years (100/4); 250 in a thousand (25*10)..
and only 2 from 2001 to 3001 are multiples of 400 (2400, 2800), so subtract 8
250-8 = 242

Perfect 🙂 well done!