is 291 divisble by 3? why or why not?

Answer 1

Yes!

"Divisible by" means that you can divide a number by another number without having anything left over. For example, 10 is not divisible by 3 because you have 1/3 left over. 15 is divisible by 3 because you get 5, with zero left over.


A trick for determining whether a number is divisible by 3 is to add up all the digits. If the number you end up with is divisible by 3, then the original number is also divisible by 3. It really works!

In your example: 291 -> 2+9+1 = 12.

12 is divisible by 3. So, 291 is also divisible by 3.


And as it turns out, 291 divided by 3 is 97.


This is really handy when you have massive numbers and no calculator.

For example, 514123092. Is it divisible by 3? Yes, because it adds up to 27.


(In other news, all numbers divisible by 2 are even, and all numbers divisible by 5 end in 5 or 0.)

May God bless you.

Answer 2

Yes. The quotient is 97. But there is an easy way to tell without actually doing the division: add the digits in 291, giving 12, and add those digits giving 3. (You can ignore any 9 digit that arises along the way, which means that you can go directly from 291 to 3.) If the result is a multiple of 3, the original number is also; if the result is 0, the original number is a multiple of 9. The process is called casting out 9's.

Answer 3

3 x 97 = 291

Answer 4

Yes, because when you divide by 3, you get 97 with no remainder.

The quick way to tell is to add the digits in the number: so for 291, you add 2 + 9 + 1 = 12, and then since 12 is evenly divisible by 3, so is the original number 291.

Answer 5

Yes. The sum of the digits of 291 is 12, which
is a multiple of 3, so 291 is also.
In fact, 291 = 97*3.