My favorite way to approach a math question is simply to draw a picture!
Step #1: Draw the picture
Imagine below each bracket is a vase... I will label each vase by a letter:
Vase A: [ ] Vase D: [ ] Vase G: [ ]
Vase B: [ ] Vase E: [ ] Vase H: [ ]
Vase C: [ ] Vase F: [ ] Vase J: [ ]
Step #2: Fill the Vase
Now I will go and add ONE rose to each vase at a time. Once I put the last rose in "Vase J", go back to the beginning to "Vase A" and add another rose. Repeat this until you run out of roses.
Here is what it may look like when you start to draw it. ( The * means a rose)
Vase A: [ * ] Vase D: [ ] Vase G: [ ]
Vase B: [ * ] Vase E: [ ] Vase H: [ ]
Vase C: [ * ] Vase F: [ ] Vase J: [ ]
The next rose I would add would be to "Vase D"
Step 4: Answer the question!
Now that my vases are filled, double check that each vase has the same number of roses.
Once you have double checked your drawing, how many roses are in each vase?
Vase A: [ * * * ] Vase D: [ * * * ] Vase G: [* * * ]
Vase B: [ * * * ] Vase E: [ * * * ] Vase H: [* * * ]
Vase C: [ * * * ] Vase F: [ * * * ] Vase J: [ * * * ]
Answer: There are 3 roses in each vase!