The Guess Card

This guess card is a puzzle made from 2-base number system. To determine how much card is needed, we must take the range of the age we will guess. For example, we will guess the age of the boy whose range 1-15 years old, so here we need 4 cards. Here we use the relation between 10-base number and 2-base number. With the four first 2-base numbers we can make 24-1 combination. So that cards contain till 15 numbers, and so on. Let’s look like the picture:

If the child who his age is guess say that his age is in the card A, C and D then the child’s age definitely 13. Where is the number from???
The 13 number is the sum of the smallest number in the A, C and D cards. They are 1+4+8 = 13.
Try the other number… :)
Next time I try to make some application to generate this card, so you can play this game. See next…