Difference between revisions of "1986 AJHSME Problems/Problem 12"
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==Solution== | ==Solution== | ||
| − | + | We need to find the number of those who did get the same on both tests over 30 (the number of students in the class). | |
| − | So, we have | + | So, we have <cmath>\frac{2 + 4 + 5 + 1}{30}</cmath> |
| − | + | Which simplifies to <cmath>\frac{12}{30} = \frac{4}{10} = \frac{40}{100} = 40 \%</cmath> | |
| − | |||
| − | Which simplifies to | ||
| − | |||
| − | < | ||
| − | |||
| − | |||
| + | <math>\boxed{\text{D}}</math> | ||
==See Also== | ==See Also== | ||
| − | [[ | + | {{AJHSME box|year=1986|num-b=11|num-a=13}} |
| + | [[Category:Introductory Algebra Problems]] | ||
| + | {{MAA Notice}} | ||
Latest revision as of 20:16, 3 July 2013
Problem
The table below displays the grade distribution of the 
students in a mathematics class on the last two tests. For example, exactly one student received a 'D' on Test 1 and a 'C' on Test 2 (see circled entry). What percent of the students received the same grade on both tests?
![[asy] draw((2,0)--(7,0)--(7,5)--(2,5)--cycle); draw((3,0)--(3,5)); draw((4,0)--(4,5)); draw((5,0)--(5,5)); draw((6,0)--(6,5)); draw((2,1)--(7,1)); draw((2,2)--(7,2)); draw((2,3)--(7,3)); draw((2,4)--(7,4)); draw((.2,6.8)--(1.8,5.2)); draw(circle((4.5,1.5),.5),linewidth(.6 mm)); label("0",(2.5,.2),N); label("0",(3.5,.2),N); label("2",(4.5,.2),N); label("1",(5.5,.2),N); label("0",(6.5,.2),N); label("0",(2.5,1.2),N); label("0",(3.5,1.2),N); label("1",(4.5,1.2),N); label("1",(5.5,1.2),N); label("1",(6.5,1.2),N); label("1",(2.5,2.2),N); label("3",(3.5,2.2),N); label("5",(4.5,2.2),N); label("2",(5.5,2.2),N); label("0",(6.5,2.2),N); label("1",(2.5,3.2),N); label("4",(3.5,3.2),N); label("3",(4.5,3.2),N); label("0",(5.5,3.2),N); label("0",(6.5,3.2),N); label("2",(2.5,4.2),N); label("2",(3.5,4.2),N); label("1",(4.5,4.2),N); label("0",(5.5,4.2),N); label("0",(6.5,4.2),N); label("F",(1.5,.2),N); label("D",(1.5,1.2),N); label("C",(1.5,2.2),N); label("B",(1.5,3.2),N); label("A",(1.5,4.2),N); label("A",(2.5,5.2),N); label("B",(3.5,5.2),N); label("C",(4.5,5.2),N); label("D",(5.5,5.2),N); label("F",(6.5,5.2),N); label("Test 1",(-.5,5.2),N); label("Test 2",(2.6,6),N); [/asy]](http://latex.artofproblemsolving.com/4/5/6/456c4e5a5c3b5f6db20d14b617ecd66f31f0ad66.png)
Solution
We need to find the number of those who did get the same on both tests over 30 (the number of students in the class).
So, we have ![\[\frac{2 + 4 + 5 + 1}{30}\]](http://latex.artofproblemsolving.com/e/4/c/e4c8506174d48db464ceb2cc315a5b429eea5118.png)
Which simplifies to ![\[\frac{12}{30} = \frac{4}{10} = \frac{40}{100} = 40 \%\]](http://latex.artofproblemsolving.com/6/7/0/670d59e76b1a54370833ae32bddcea88c597e249.png)
See Also
| 1986 AJHSME (Problems • Answer Key • Resources) | ||
| Preceded by Problem 11 |
Followed by Problem 13 | |
| 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
| All AJHSME/AMC 8 Problems and Solutions | ||
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. 
