<think>Okay, let me try to figure out how many flowers Mark has in his garden. So, he has three colors: yellow, purple, and green. The problem gives specific percentages about how many more purple flowers there are compared to yellow, and how many green flowers there are relative to yellow and purple combined. I need to break this down step by step to avoid getting confused.

First, let's start with what we know. Ten of the flowers are yellow. That seems straightforward. Then it says there are 80% more purple flowers than yellow ones. Hmm. Okay, so if there are 10 yellow, then purple is 10 plus 80% of 10. Let me check. To calculate 80% more, you take the original amount and add 80% of it. So 10 yellow flowers, 80% of 10 is 8, so adding that to the original 10 gives 18 purple flowers. Wait, actually, 100% + 80% = 180%, so 10 * 1.8 = 18. Yeah, that seems right. So purple flowers are 18.

Next, the green flowers. The problem states there are only 25% as many green flowers as there are yellow and purple flowers combined. Alright, so first I need to compute the total number of yellow and purple flowers. Let's add those up: yellow is 10, purple is 18, so 10 + 18 = 28. Then 25% of that number would be the number of green flowers. So 25% is the same as a quarter, right? So 28 divided by 4 is 7. So, maybe 7 green flowers?

Alternatively, 25% as many green as yellow and purple. So total for green would be 0.25*(10 + 18). Let me calculate that again: 10 + 18 is 28, 28 * 0.25 = 7. Yes, that seems correct. So green flowers are 7.

Now, to find the total number of flowers in the garden, I need to add up all three colors. So yellow (10) + purple (18) + green (7). Let me calculate that sum. 10 + 18 is 28, 28 + 7 is 35. So does Mark have 35 flowers in total?

Wait, let me double-check the steps to make sure I didn't make an arithmetic mistake. 

Starting with yellow: 10. Correct.

Purple: 80% more than yellow. 10 + 80% of 10. 80% of 10 is 8, so 10 + 8 = 18. That seems correct. 10 * 1.8 = 18. Yup.

Yellow and purple together: 10 + 18 = 28. Correct.

Green: 25% of that total. So 25% of 28. Well, 10% of 28 is 2.8, so 20% is 5.6, 5% is 1.4, adding 20% +5% gives 25%, which is 5.6 +1.4 = 7. Or 28 divided by 4 is 7. Either way comes to 7. So green is 7. That adds up.

Total flowers: 10 +18 +7. 10+18=28, 28+7=35. Yep, that seems right. So 35 flowers total.

Hmm, is there any possibility I might have misinterpreted the percentage for the green flowers? The problem states "25% as many green flowers as there are yellow and purple flowers." So, green = 0.25*(yellow + purple). That's how I calculated 0.25*(28). So yes, that interpretation is correct. If it had been 25% more, that would differ, but it's specified as "only 25% as many," which means it's a quarter of the combined yellow and purple. So my calculation stands.

Therefore, adding all three, the total is 10 + 18 + 7 = 35. That should be the answer. Let me just retrace all steps once again to ensure I didn't skip anything.

Yellow: Clear, 10.

Purple: 80% more than yellow. Check.

Green: 25% as much as combined yellow and purple. Check. Also calculated correctly.

Add them up. Check.

Yes, I think that all checks out. I don't see any errors in the reasoning here.
</think>

Mark started with 10 yellow flowers.  

**Purple Flowers Calculation:**  
There are 80% more purple flowers than yellow.  
- 80% of 10 = 0.8 × 10 = **8**  
- Total purple flowers = 10 + 8 = **18**  

**Green Flowers Calculation:**  
Green flowers are 25% of the combined total of yellow and purple.  
- Combined yellow and purple = 10 + 18 = **28**  
- 25% of 28 = 0.25 × 28 = **7**  

**Total Flowers:**  
Sum all colors:  
**10 (yellow) + 18 (purple) + 7 (green) = 35**  

**Answer:**  
\boxed{35}