1989 AJHSME Problems/Problem 9

Revision as of 20:48, 5 June 2009 by 5849206328x (talk | contribs) (New page: ==Problem== There are <math>2</math> boys for every <math>3</math> girls in Ms. Johnson's math class. If there are <math>30</math> students in her class, what percent of them are boy...)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Problem

There are $2$ boys for every $3$ girls in Ms. Johnson's math class. If there are $30$ students in her class, what percent of them are boys?

$\text{(A)}\ 12\% \qquad \text{(B)}\ 20\% \qquad \text{(C)}\ 40\% \qquad \text{(D)}\ 60\% \qquad \text{(E)}\ 66\frac{2}{3}\%$

Solution

Besides ensuring the situation is possible, the $30$ students information is irrelevant.

From the first statement, we can deduce that $2$ of every $2+3=5$ students are boys. Thus, $2/5=40\% \rightarrow \boxed{\text{C}}$ of the students are boys.

See Also

1989 AJHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 8
Followed by
Problem 10
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