A few weeks ago a number challenge arrived via Facebook.Your answers are accepted any time until midnight Eastern Time on Sunday, on our Family Puzzle Marathon.
It said that the following problem can be solved by pre-school children in 5-10 minutes, by programmers - in 1 hour, by people with higher education... well, check it yourself!
I thought and thought and thought and couldn't figure it out. Pre-schoolers! It must be something not related to any kind of computation. Numbers, shapes, squiggles... After a while I cheated and found the solution on the web.
It is the number of loops in the digits.
2581 will have only 2 loops in the digit 8, so 2581=2
To boost self-confidence of those who like me couldn't solve this pre-schooler challenge I am offering another one that uses a bit more math wisdom:
What is the next number in the following sequence:
-2, 4, -12, 48, -240, ?