Answer
The answer is as follows. 
1. Put '5' on A-f
2. Put '5' on D-f
3. Put '5' on C-f
4. Put '4' on C-e
5. Put '4' on C-c
6. Put '3' on C-d
7. Put '5' on C-b
8. Put '5' on D-b
9. Put '2' on E-b
Katrielle and the Millionaires' Conspiracy walkthrough
Puzzle Location: Bulk Buyears' Bargain Basement
Shoot bubbles from the cannon to burst all of the bubbles floating in the air.
To pop bubbles, you need to form a chain linking bubbles of the same number horizontally and/or vertically.
The chain needs to contain at least as many bubbles as the number displayed on the bubbles in it.
Slide bubbles from the cannon on the left into empty spaces to fire.
The bubbles in the cannon are replanished with each shot, but you need to burst all of them within the maximum shot limit.
If there are not enough bubbles of a certain number, you need to add to them by firing bubbles from the cannon.
There are several ways to do this, but let's take one example.
First, concentrate on the '5' bubbles on the right-hand side.
By placing more '5' bubbles at the top and bottom, you should be able to pop them all at the same time.
Continuing on from hint two...
If you place your bubbles carefully, you should be able to eliminate the '5' bubbles on the right-hand side in three shots.
Next, focus on the '4' bubbles, and try to pop lots of them in one go like you did with '5'.
Continuing on from hint three...
If you place your bubbles carefully, you should be able to eliminate all of the '4' bubbles in two shots.
Then you just need to pay attention to how many shots you have remaining as you pop the remainder of the bubbles.
The answer is as follows.
1. Put '5' on A-f
2. Put '5' on D-f
3. Put '5' on C-f
4. Put '4' on C-e
5. Put '4' on C-c
6. Put '3' on C-d
7. Put '5' on C-b
8. Put '5' on D-b
9. Put '2' on E-b