Fortune Telling Collection - Comprehensive fortune-telling - With enough 1, 2, and 5 cents, how many ways can you earn 1 yuan?

With enough 1, 2, and 5 cents, how many ways can you earn 1 yuan?

Only 1 minute: 1 species.

Only 2 points: 1 species.

Only 5 points: 1 species.

Only 1, 2: 49 species.

There are only 1, 5: 19 species.

There are only 2, 5: 9 kinds

There are 1, 2,5: 461species.

There are some cases in 1, 2 and 5. Explanation:

1 cent is divided into parity:

Special case: If there is 1 or 3, then there are 10 methods; If there are 2, 4, 6, 8 or 5, 7, 9, 1 1, 13, there are 9 methods. So there is a special case of 2 *10+9 * 9 =101.

General situation: 10, 12, 14, 16, 18 or 15, 17,19,2. And so on until there are 80, 82, 84, 86, 88 or 85, 87, 89, 9 1, 93 methods. There are10 * (8+7+6+5+4+3+2+1) = 360 species.

So generally speaking, there are101+360 = 461species * *.

All the situations add up to 54 1 species.

Link:/question/21075235/answer/17095924.

Source: Zhihu.