# The answer to this question 180, but how? One day 10% of the students enrolled in the school were absent, There were 1620 student present on that day. How may students were absent. I know you have to figure what percent of the students were present.

I'm going to show you two ways to do it. Way #1 is the slogging way. Way #2 is the clever way. Way #1: ' One hundred percent ' means ALL of something. ALL of the students in the school is the same as 100% of them. If 10% are absent, then 90% are present. 90% means 0.9 . 1620 students = 90% of the school. 1620 = 0.9 x school total Divide each side by 0.9: 1620/0.9 = total school 1800 = total school How many were absent ? 10% of them. 10% means 0.10 . 0.10 x 1800 = 180 students absent . _______________________________________ Way #2: ' One hundred percent ' means ALL of something. ALL of the students in the school is the same as 100% of them. ==> If 10% are absent, then 90% are present. ==> The number of students present is 9 times the number who are absent. 1620 = 9 x the number absent Divide each side by 9 : 1620 / 9 = the number absent 1620 / 9 = 180 absent .