Originally Posted by

**soilquestions**
I am solving the following problem:

"A soil sample contains 10 grams of organic matter, 30 grams of water and weighs 90 grams. There is 60% of sand, 10 grams of silt (the rest of the mineral fraction is clay)."

I am to convert the sand percentage into grams. Mathematically, I know how to do this but I am unsure of what it is a percentage of. I am assuming I subtract the amount of water and organic matter from the overall weight (90 grams), which equals 50 grams. So is the sand 60% of 50 grams?