Tuesday, 10 January

Today is 10 day of the year.
10 = 2 x 5
10 is one of only 5 numbers that are both a triangular and a tetrahedral number.
10 = 2 + 3 + 5 i.e. it is the sum of the first three prime numbers.
10 is a happy number.
There are 10 ways to choose 3 objects from 5 objects where order is not important.
Let the five objects be the letters A, B, C, D and E.
The 10 combinations of these letters are
A, B, C
A, B, D
A, B, E
A, C, D
A. C. E
A, D, E
B, C, D
B, C, E
B, D, E
C, D, E