Question

how many three digit multiple of 3 can be written using numbers 1,3,5,9 if all digits are different​

Answer 1

Answer:

195, 531, 591, 135, 315, 351 etc.

Step-by-step explanation:

it is totally infinite

Answer 2

The answer is 12.

Given:

The numbers 1,3,5,9

To Find:

Three-digit multiples of 3 that can be made using the numbers 1,3,5,9

Solution:

For a number to be a multiple of 3, the sum of the numbers should be divisible by 3.

Hence three digit numbers divisible by 3 are

• 135 as 1+3+5=9 which is divisible by 3
• 153 as 1+3+5=9 which is divisible by 3
• 315 as 1+3+5=9 which is divisible by 3
• 351 as 1+3+5=9 which is divisible by 3
• 513 as 1+3+5=9 which is divisible by 3
• 531 as 1+3+5=9 which is divisible by 3
• 159 as 1+5+9=15 which is divisible by 3
• 195 as 1+5+9=15 which is divisible by 3
• 519 as 1+5+9=15 which is divisible by 3
• 591 as 1+5+9=15 which is divisible by 3
• 915 as 1+5+9=15 which is divisible by 3
• 951 as 1+5+9=15 which is divisible by 3

Therefore there are 12 three-digit numbers which are multiples of 3.

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