1984 AHSME Problems/Problem 1

Revision as of 06:58, 15 June 2011 by Admin25 (talk | contribs) (Created solution)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Problem

$\frac{1000^2}{252^2-248^2}$ equals

$\mathrm{(A) \  }62,500 \qquad \mathrm{(B) \  }1,000 \qquad \mathrm{(C) \  } 500\qquad \mathrm{(D) \  }250 \qquad \mathrm{(E) \  } \frac{1}{2}$

Solution

We can use difference of squares to factor the denominator, yielding:

$\frac{1000^2}{252^2-248^2}=\frac{1000^2}{(252-248)(252+248)}=\frac{1000^2}{(4)(500)}=\frac{1000^2}{1000}$.

We see that the $1000$ in the denominator cancels with one of the $1000$s in the numerator, yielding $1000, \boxed{\text{B}}$.

See Also

1984 AHSME (ProblemsAnswer KeyResources)
Preceded by
First Problem
Followed by
Problem 2
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 26 27 28 29 30
All AHSME Problems and Solutions