Difference between revisions of "2011 AMC 10A Problems/Problem 10"
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==Problem 10== | ==Problem 10== | ||
| − | A majority of the 30 students in Ms. | + | A majority of the 30 students in Ms. Demeanor's class bought pencils at the school bookstore. Each of these students bought the same number of pencils, and this number was greater than 1. The cost of a pencil in cents was greater than the number of pencils each student bought, and the total cost of all the pencils was <math>\</math><math>17.71</math>. What was the cost of a pencil in cents? |
<math>\text{(A)}\,7 \qquad\text{(B)}\,11 \qquad\text{(C)}\,17 \qquad\text{(D)}\,23 \qquad\text{(E)}\,77</math> | <math>\text{(A)}\,7 \qquad\text{(B)}\,11 \qquad\text{(C)}\,17 \qquad\text{(D)}\,23 \qquad\text{(E)}\,77</math> | ||
Revision as of 18:22, 21 February 2011
Problem 10
A majority of the 30 students in Ms. Demeanor's class bought pencils at the school bookstore. Each of these students bought the same number of pencils, and this number was greater than 1. The cost of a pencil in cents was greater than the number of pencils each student bought, and the total cost of all the pencils was 
. What was the cost of a pencil in cents?
Solution
Let 
be the number of students at the bookstore, 
be the number of pencils each student bought, and 
be the price of one pencil. We see that 
. Then we must have 
by the original conditions and the answer is 
.
