When choosing and putting three sheets in order out of four cards, 0, 1, 3, and 4 and making the number of three digits, how many ways of number of multiple of 2 are made?
Answer
10 ways
Solution
In this case, it is considered to two cases of placing 4 or 0 in ones digit.
In case that 0 placed in ones digit, since the number of hundreds digit is chosen from three cards, it is three ways.
The number of tens digit is chosen from the remaining two cards.
Thus, it is 3 × 2 = 6 ways.
Thus, it is 3 × 2 = 6 ways.
In case that 4 is used in ones digit, since the number of hundreds digit is chosen from 1 or 3, it is two ways.
The number of tens digit is chosen from 0 or the number not chosen in hundreds digit .
Thus, it is 2 × 2 = 4 ways.
Therefore it is 6 + 4 = 10 ways in total.
