High School

A five-digit number divisible by 3 is to be formed using the digits 0, 1, 2, 3, 4, and 5, without repetition. What is the total number of ways this can be done?

A. 216
B. 240
C. 600
D. 3125

Answer :

Final answer:

Using properties of numbers divisible by 3 and considering the restriction on leading digit, the total number of ways a five-digit number divisible by 3 can be formed from the digits 0, 1, 2, 3, 4, and 5 without repetition is 600. The correct answer is option c.

Explanation:

To find the total number of ways a five-digit number can be formed from the digits 0, 1, 2, 3, 4, and 5 without repetition and divisible by 3, we first need to consider the properties of numbers divisible by 3. A number is divisible by 3 if the sum of its digits is divisible by 3. We have six digits, which sum up to 0 + 1 + 2 + 3 + 4 + 5 = 15, a number divisible by 3, meaning any combination of these digits without repetition will also result in a number divisible by 3.

However, we need to be careful with the digit '0' as it cannot be the leading digit. There are 5 options for the first digit (1, 2, 3, 4, or 5), followed by any one of the remaining 5 digits for the second position, 4 for the third, 3 for the fourth, and 2 for the last which includes '0' since it can now be used. So the formula for the permutation without repeats would yield the total ways as 5 * 5 * 4 * 3 * 2 = 600 ways.