PUZZLE

12 Days Of Christmas

According to the traditional song, on the first day of Christmas (25th December), my true love sent to me:

. A partridge in a pair tree 

On the second day of Christmas (26th December), my true love sent to me THREE presents:

. Two turtle doves
. A partridge in a pear tree 

On the third day of Christmas (27th December and so on) my true love sent to me SIX presents:

. Three French hens
. Two turtle doves
. A partridge in a pear tree 

This carries on until the the twelfth day of Christmas, when my true love sends me:

Twelve drummers drumming
Eleven pipers piping
Ten lords a-leaping
Nine ladies dancing
Eight maids a-milking
Seven swans a-swimming
Six geese a-laying
Five gold rings
Four calling birds
Three French hens
Two turtle doves
A partridge in a pear tree 

After the twelve days of Christmas are over, how many presents has my true love sent me altogether?

Solution

1 + 3 + 6 + 10 + 15 + 21 + 28 + 36 + 45 + 55 + 66 + 78 = 364 presents

Which is really interesting when you think there are 365 days in a typical year!