What is 90 of 20?

The expression "90 of 20" seems to be a combination of two numbers and a preposition. However, mathematically, the given phrase is not clear or meaningful. It is not clear what operation or calculation is intended between 90 and 20.

If the intention is to calculate a percentage, which is often denoted by the word "of," then "90 of 20" would mean finding 90% of 20. In that case, the calculation would be:

90% of 20 = 0.90 x 20 = 18

So, if "90 of 20" refers to finding 90% of 20, the result would be 18. However, without further context or information, it is difficult to determine the exact meaning or intended calculation of the phrase "90 of 20."