Puzzles

In the song The Twelve Days of Christmas, how many presents have been given after 8 days?

22 is two times an odd number. Today's number is the mean of all the answers on days (including today) that are two times an odd number.

The factors of 6 (excluding 6 itself) are 1, 2 and 3. \(1+2+3=6\), so 6 is a perfect number.

Today's number is the only three digit perfect number.

What is the largest number that cannot be written in the form \(10a+27b\), where \(a\) and \(b\) are nonnegative integers (ie \(a\) and \(b\) can be 0, 1, 2, 3, ...)?

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the products are correct. Today's number is the smallest number that can be made using the digits in the red boxes.

Today's number is the maximum number of pieces that a (circular) pancake can be cut into with 17 straight cuts.

Arrange the digits 1-9 in a 3×3 square so that every row makes a three-digit square number, the first column makes a multiple of 7 and the second column makes a multiple of 4. The number in the third column is today's number.

There are 204 squares (of any size) in an 8×8 grid of squares. Today's number is the number of rectangles (of any size) in a 2×19 grid of squares