Puzzles
Factorial pattern
$$1\times1!=2!-1$$ $$1\times1!+2\times2!=3!-1$$ $$1\times1!+2\times2!+3\times3!=4!-1$$Does this pattern continue?
24 December
Today's number is 191 more than one of the other answers and
100 less than another of the answers.
23 December
Today's number is the number of three digit numbers that are not three more than a multiple of 7.
22 December
Today's number is a palindrome. Today's number is also the number of palindromes between 111 and 11111 (including 111 and 11111).
19 December
The sum of all the numbers in the eighth row of Pascal's triangle.
Clarification: I am starting the counting of rows from 1, not 0. So (1) is the 1st row, (1 1) is the 2nd row, (1 2 1) is the 3rd row, etc.
18 December
The smallest number whose sum of digits is 25.
16 December
Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums are correct. The sums should be read left to right and top to bottom ignoring the usual order of operations. For example, 4+3×2 is 14, not 10.
Today's number is the largest number than can be made from the digits in red boxes.
| × | × | = 6 | |||
| × | × | × | |||
| × | × | = 180 | |||
| × | × | × | |||
| × | × | = 336 | |||
| = 32 | = 70 | = 162 |
15 December
A book has 386 pages. What do the page numbers on the two middle pages add up to?