Customers at an ice cream shop took a survey. The results showed that 144 customers rated the shop as being "ver satisfactory." This number represented 45% of the total number of customers who took the survey.
What was the total number of customers who took the survey?
There are 90 girls and 60 boys in the sixth grade at a middle school. Of these students, 9 girls and 3 boys write left-handed. What percentage of the sixth graders at this middle school write left-handed?