There are 81 women teachers at Russell High. If 45% of the teachers in the school are women, how many teachers are there at Russell High?
Use the proportion part/whole = %/100. Part is the number of female teachers (81). Whole is what we are looking for; call it x; the % is 45; 81/x = 45/100. Cross multiply; (81)(100) = 45x. Divide both sides by 45 to solve for x; 8,100/45, 45x/45;x = 180