MathDB

1958 AMC 12/AHSME

Part of AMC 12/AHSME

Subcontests

(50)

Broken Line Path

Diameter AB \overline{AB} of a circle with center O O is 10 10 units. C C is a point 4 4 units from A A, and on AB \overline{AB}. D D is a point 4 4 units from B B, and on AB \overline{AB}. P P is any point on the circle. Then the broken-line path from C C to P P to D D: <spanclass=latexbold>(A)</span> has the same length for all positions of P<spanclass=latexbold>(B)</span> exceeds 10 units for all positions of P<spanclass=latexbold>(C)</span> cannot exceed 10 units<spanclass=latexbold>(D)</span> is shortest when CPD is a right triangle<spanclass=latexbold>(E)</span> is longest when P is equidistant from C and D. <span class='latex-bold'>(A)</span>\ \text{has the same length for all positions of }{P}\qquad\\ <span class='latex-bold'>(B)</span>\ \text{exceeds }{10}\text{ units for all positions of }{P}\qquad \\ <span class='latex-bold'>(C)</span>\ \text{cannot exceed }{10}\text{ units}\qquad \\ <span class='latex-bold'>(D)</span>\ \text{is shortest when }{\triangle CPD}\text{ is a right triangle}\qquad \\ <span class='latex-bold'>(E)</span>\ \text{is longest when }{P}\text{ is equidistant from }{C}\text{ and }{D}.

Error in a Check

A check is written for x x dollars and y y cents, x x and y y both two-digit numbers. In error it is cashed for y y dollars and x x cents, the incorrect amount exceeding the correct amount by $17.82 \$17.82. Then: <spanclass=latexbold>(A)</span> x cannot exceed 70<spanclass=latexbold>(B)</span> y can equal 2x<spanclass=latexbold>(C)</span> the amount of the check cannot be a multiple of 5<spanclass=latexbold>(D)</span> the incorrect amount can equal twice the correct amount<spanclass=latexbold>(E)</span> the sum of the digits of the correct amount is divisible by 9 <span class='latex-bold'>(A)</span>\ {x}\text{ cannot exceed }{70}\qquad \\ <span class='latex-bold'>(B)</span>\ {y}\text{ can equal }{2x}\qquad\\ <span class='latex-bold'>(C)</span>\ \text{the amount of the check cannot be a multiple of }{5}\qquad \\ <span class='latex-bold'>(D)</span>\ \text{the incorrect amount can equal twice the correct amount}\qquad \\ <span class='latex-bold'>(E)</span>\ \text{the sum of the digits of the correct amount is divisible by }{9}

Conclusion From Statements

Given the true statements: (1) If a a is greater than b b, then c c is greater than d d (2) If c c is less than d d, then e e is greater than f f. A valid conclusion is: <spanclass=latexbold>(A)</span> If a is less than b, then e is greater than f<spanclass=latexbold>(B)</span> If e is greater than f, then a is less than b<spanclass=latexbold>(C)</span> If e is less than f, then a is greater than b<spanclass=latexbold>(D)</span> If a is greater than b, then e is less than f<spanclass=latexbold>(E)</span> none of these <span class='latex-bold'>(A)</span>\ \text{If }{a}\text{ is less than }{b}\text{, then }{e}\text{ is greater than }{f}\qquad \\ <span class='latex-bold'>(B)</span>\ \text{If }{e}\text{ is greater than }{f}\text{, then }{a}\text{ is less than }{b}\qquad \\ <span class='latex-bold'>(C)</span>\ \text{If }{e}\text{ is less than }{f}\text{, then }{a}\text{ is greater than }{b}\qquad \\ <span class='latex-bold'>(D)</span>\ \text{If }{a}\text{ is greater than }{b}\text{, then }{e}\text{ is less than }{f}\qquad \\ <span class='latex-bold'>(E)</span>\ \text{none of these}

Steers and Cows

With $1000 \$1000 a rancher is to buy steers at $25 \$25 each and cows at $26 \$26 each. If the number of steers s s and the number of cows c c are both positive integers, then: <spanclass=latexbold>(A)</span> this problem has no solution<spanclass=latexbold>(B)</span> there are two solutions with s exceeding c<spanclass=latexbold>(C)</span> there are two solutions with c exceeding s<spanclass=latexbold>(D)</span> there is one solution with s exceeding c<spanclass=latexbold>(E)</span> there is one solution with c exceeding s <span class='latex-bold'>(A)</span>\ \text{this problem has no solution}\qquad\\ <span class='latex-bold'>(B)</span>\ \text{there are two solutions with }{s}\text{ exceeding }{c}\qquad \\ <span class='latex-bold'>(C)</span>\ \text{there are two solutions with }{c}\text{ exceeding }{s}\qquad \\ <span class='latex-bold'>(D)</span>\ \text{there is one solution with }{s}\text{ exceeding }{c}\qquad \\ <span class='latex-bold'>(E)</span>\ \text{there is one solution with }{c}\text{ exceeding }{s}