If I have 10 pens and sold 8 which leave me with 8. What is the percentages

Okay, this doesn't make sense. First off, you are left with 2 pens. Second, the percentage of what? If you clarify, I could help you...

What percent of 36 is 90?

To calculate the percentage, you need to determine what portion the number sold (8) is of the original number (10), and then multiply that fraction by 100.

Step 1: Determine the fraction:
Number sold / Original number = 8 / 10 = 0.8

Step 2: Multiply the fraction by 100 to get the percentage:
0.8 * 100 = 80%

So, if you have 10 pens and sold 8, you are left with 80% of the original amount.