Difference between revisions of "1995 AJHSME Problems/Problem 14"
Mrdavid445 (talk | contribs) (Created page with "==Problem== A team won <math>40</math> of its first <math>50</math> games. How many of the remaining <math>40</math> games must this team win so it will have won exactly <math>...") |
(→Problem) |
||
| Line 4: | Line 4: | ||
<math>\text{(A)}\ 20 \qquad \text{(B)}\ 23 \qquad \text{(C)}\ 28 \qquad \text{(D)}\ 30 \qquad \text{(E)}\ 35</math> | <math>\text{(A)}\ 20 \qquad \text{(B)}\ 23 \qquad \text{(C)}\ 28 \qquad \text{(D)}\ 30 \qquad \text{(E)}\ 35</math> | ||
| + | |||
| + | ==Solution== | ||
| + | |||
| + | Noting that 70% is the same as <math>\frac{70}{100}=\frac{7}{10}</math>, and that, when x is the amount of wins in the last 40 games, the fraction of games won is <math>\frac{40+x}{50+40}=\frac{40+x}{90}</math>, all we have to do is set them equal: <cmath>\frac{40+x}{90}=\frac{7}{10}</cmath> <cmath>40+x=63</cmath> <cmath>x=23 \text{(B)}</cmath> | ||
Revision as of 13:48, 5 July 2012
Problem
A team won 
of its first 
games. How many of the remaining games must this team win so it will have won exactly 
of its games for the season?
Solution
Noting that 70% is the same as 
, and that, when x is the amount of wins in the last 40 games, the fraction of games won is 
, all we have to do is set them equal: ![\[\frac{40+x}{90}=\frac{7}{10}\]](http://latex.artofproblemsolving.com/c/9/c/c9cf5b2c78d072905953eef21e233fd83893ab69.png)
![\[40+x=63\]](http://latex.artofproblemsolving.com/9/a/8/9a8821ded51adcd10d6092091fd227d2d9fa0fac.png)
![\[x=23 \text{(B)}\]](http://latex.artofproblemsolving.com/3/7/a/37adc05c1d5fc4e1f9eb694951a72527512b84b3.png)
