Sure, let's solve the problem step by step:

Step 1: Calculate the number of red balloons:

Given that 40% of the balloons were red, we can find the total number of red balloons using the following formula:

Number of red balloons = (40/100) * Total number of balloons

Since there were a thousand balloons in total, the number of red balloons is:

Number of red balloons = (40/100) * 1000 = 400

Step 2: Calculate the number of green, blue, and pink balloons combined:

We know that the rest of the balloons (after accounting for the red balloons) were equally divided between green, blue, and pink balloons. Let's first calculate the total number of green, blue, and pink balloons combined.

Total number of green, blue, and pink balloons = Total number of balloons - Number of red balloons

Total number of green, blue, and pink balloons = 1000 - 400 = 600

Step 3: Calculate the number of each green, blue, and pink balloons:

Since the remaining balloons were equally divided, we can find the number of each type of balloon using the following formula:

Number of each type of balloon = (Total number of green, blue, and pink balloons) / 3

Number of each type of balloon = 600 / 3 = 200

So, there are 200 green, 200 blue, and 200 pink balloons each.

Step 4: Calculate the balloons left after the party:

After the party, only 10% of the red and green balloons and 5% of the blue and pink balloons remained.

Remaining red balloons = 10% of the red balloons = (10/100) * 400 = 40

Remaining green balloons = 10% of the green balloons = (10/100) * 200 = 20

Remaining blue balloons = 5% of the blue balloons = (5/100) * 200 = 10

Remaining pink balloons = 5% of the pink balloons = (5/100) * 200 = 10

Therefore, after the party, there are 40 red balloons, 20 green balloons, 10 blue balloons, and 10 pink balloons left.