Difference between revisions of "2007 AMC 12B Problems/Problem 10"
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First, determine the total number of people in the group. | First, determine the total number of people in the group. | ||
− | <math>2= | + | <math>2=(40/100-30/100)t</math> |
<math>t=200/10=20</math> | <math>t=200/10=20</math> |
Revision as of 04:43, 1 September 2008
Problem
Some boys and girls are having a car wash to raise money for a class trip to China. Initially % of the group are girls. Shortly thereafter two girls leave and two boys arrive, and then
% of the group are girls. How many girls were initially in the group?
Solution
First, determine the total number of people in the group.
Now find the original number of girls:
So, there are 8 girls,