# Math

posted by .

I want to make sure I'm doing the GCF correctly with 3 numbers. The problem is: Ari is making patriotic pins. He has 105 red ribbons, 147 white ribbons, and 189 blue ribbons. What is the greatest number of identical pins he can make if he uses all his ribbons? I think the answer is 21. Is that correct? Thanks..

• Math -

21 is correct.
When in doubt, do one of the following:
1. Find GCF for two numbers at a time, the first time using two original numbers. The second time use the first GCF and the third number.
2. Divide each original number by the GCF found. If the numbers don't divide, there is a mistake. If there is a GCF between the three GCFs, then some factors were missing from the original GCF.

## Similar Questions

1. ### math

A midwestern music competition awarded 38 ribbons. The number of blue ribbons awarded was 3 less than the number of white ribbons. The number of red ribbons was 2 more than the number of white ribbons. How many of each kind of ribbon …
2. ### algebra

A midweseren music competition awarde 34 ribbons. The number of blue ribons awarded was 2 less than the number of white ribbons. THe number of red ribons was 3 more than the number of white ribbons. How many of eah kind of ribbon awarded
3. ### math

a midwestern music competition awarded 32 ribbons. the number of blue ribbons awarded was 3 less than the number of white ribbons. the number of red ribbons was 2 more than the number of white ribbons. how many of each kind of ribbon …
4. ### College math 100

A midwestern music competition awarded 40 ribbons.The number of blue ribbons awarded was 2 less than the number of white ribbons. The number of red ribbons was 3 more than the white ribbons. How many of each kind of ribbons was awarded?
5. ### Math

Debbie has a box containing y ribbons and 4 extra ribbons. Janine has 12 ribbons. Express the number of ribbons that Sarah has in terms of y. For what value of y will Debbie and Janine have the same number of ribbons
6. ### Math

Sarah has about containing x ribbons and 4 extra ribbons. Jill's has 12 ribbons. Express the number of ribbons that Sarah has in terms of x. For what value of x will Sarah and Jill have the same number of ribbons?
7. ### math

a Midwestern music competition awarded 28 ribbons. The number of blue ribbons awarded was 1 less then the number of white ribbons. The number of red ribbons was 2 more then the number of white ribbons. How many of each kind of ribbons …
8. ### Math

Gina has 4 red ribbons, 6 times as many blue ribbons as green ribbons, and 1/4 as many green ribbons as red ribbons. How many ribbons does she have in all?
9. ### Math

The relationship of red ribbons to green ribbons is 10 : 1/4. How mini red ribbons are used for every 4 1/2 green ribbons?
10. ### Mathematics

At a local track meet, RCMS won 3 blue ribbons than red ribbons. They also won 7 more yellow ribbons than red ribbons. RCMS won a total of 28 ribbons. How many of each color did RCMS win?

More Similar Questions

Post a New Question