Try this beautiful problem from Probability .You may use sequential hints to solve the problem.
A bag contains four pieces of paper, each labeled with one of the digits 1,2,3 or 4. with no repeats. Three of these pieces are drawn, one at a time without replacement, to construct a three-digit number. What is the probability that the three-digit number is a multiple of 3?
probability
combination
Number counting
Answer: \(\frac{1}{2}\)
AMC-8, 2007 problem 24
Challenges and Thrills in Pre College Mathematics
there are two ways that The combination of digits that give multiples of 3
Can you now finish the problem ..........
The combination of digits that give multiples of 3 are (1,2,3) and (2,3,4)
can you finish the problem........
The combination of digits that give multiples of 3 are (1,2,3) and (2,3,4) . The number of ways to choose three digits out of four is 4. Therefore, the probability is \(\frac{1}{2}\)