Ninety percent of the students or 540 students attended a school assembly. How many students are there at the school

if 540 is 90% or 0.9 then 0.1 or 10% is 1/9 of 540.

540/9 is 1/9 of 540, and 10% of the school's population. that makes 60

so 540 + 60 = 100% of the school assembly.

600 students