You use a closed dot with the greater than or less than with the line under the symbol or the greater than or equal to or the less than or equal to symbols. The line indicates a closed dot.
40%less
You take 36/60
That equals 60%
This means that 36 is 60% of 60
So in 24 is 40% of 60 or 36 is 40% less than 60
24 square feet is the answer