Difference between revisions of "2007 AMC 8 Problems/Problem 1"
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== Solution == | == Solution == | ||
| − | We are looking for the average, so <math>\frac{8 + 11 + 7 + 12 + 10 + x}{6} = 10</math> | + | Let <math>x</math> be the number of hours she must work for the final week. We are looking for the average, so <math>\frac{8 + 11 + 7 + 12 + 10 + x}{6} = 10</math> |
| + | |||
| + | Solving gives: | ||
| + | |||
| + | <math>\frac{48 + x}{6} = 10</math> | ||
| + | <math>48 + x = 60</math> | ||
| + | <math>x = 12</math> | ||
| + | So, <math>\boxed{D}</math> | ||
Revision as of 14:39, 15 February 2010
Problem
Theresa's parents have agreed to buy her tickets to see her favorite band if she spends an average of 
hours per week helping around the house for 
weeks. For the first 
weeks she helps around the house for 
, 
, 
, 
and hours. How many hours must she work for the final week to earn the tickets?
Solution
Let 
be the number of hours she must work for the final week. We are looking for the average, so 
Solving gives:
So, 
