Difference between revisions of "2001 AMC 8 Problems/Problem 22"

(Slution 2)
 
(3 intermediate revisions by 2 users not shown)
Line 8: Line 8:
  
 
The highest possible score is if you get every answer right, to get <math> 5(20)=100 </math>. The second highest possible score is if you get <math> 19 </math> questions right and leave the remaining one blank, to get a <math> 5(19)+1(1)=96 </math>. Therefore, no score between <math> 96 </math> and <math> 100 </math>, exclusive, is possible, so <math> 97 </math> is not possible, <math> \boxed{\text{E}} </math>.
 
The highest possible score is if you get every answer right, to get <math> 5(20)=100 </math>. The second highest possible score is if you get <math> 19 </math> questions right and leave the remaining one blank, to get a <math> 5(19)+1(1)=96 </math>. Therefore, no score between <math> 96 </math> and <math> 100 </math>, exclusive, is possible, so <math> 97 </math> is not possible, <math> \boxed{\text{E}} </math>.
 +
 +
==Solution 2==
 +
 +
We can equivalently construct the following rules: You have 100 point at first, but if you give the wrong answer, you will lose 5 points, if you don't answer a question you will lose 4 points. Obviously, you can lose 10 points, 9 points, 8 points, 5 points or 4 points, but you cannot lose 3 points. The answer is <math> \boxed{\text{E}} </math>.
  
 
==See Also==
 
==See Also==
 
{{AMC8 box|year=2001|num-b=21|num-a=23}}
 
{{AMC8 box|year=2001|num-b=21|num-a=23}}
 
{{MAA Notice}}
 
{{MAA Notice}}

Latest revision as of 23:15, 16 June 2024

Problem

On a twenty-question test, each correct answer is worth 5 points, each unanswered question is worth 1 point and each incorrect answer is worth 0 points. Which of the following scores is NOT possible?

$\text{(A)}\ 90 \qquad \text{(B)}\ 91 \qquad \text{(C)}\ 92 \qquad \text{(D)}\ 95 \qquad \text{(E)}\ 97$

Solution

The highest possible score is if you get every answer right, to get $5(20)=100$. The second highest possible score is if you get $19$ questions right and leave the remaining one blank, to get a $5(19)+1(1)=96$. Therefore, no score between $96$ and $100$, exclusive, is possible, so $97$ is not possible, $\boxed{\text{E}}$.

Solution 2

We can equivalently construct the following rules: You have 100 point at first, but if you give the wrong answer, you will lose 5 points, if you don't answer a question you will lose 4 points. Obviously, you can lose 10 points, 9 points, 8 points, 5 points or 4 points, but you cannot lose 3 points. The answer is $\boxed{\text{E}}$.

See Also

2001 AMC 8 (ProblemsAnswer KeyResources)
Preceded by
Problem 21
Followed by
Problem 23
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. AMC logo.png