document.write( "Question 333173: three balls are randomly selected without replacement from a bag containing 20 balls numbered 1, 2 through 20. if we bet that at least one of the balls has a number greater than or equal to 17 what is the propability that we will win the bet \n" ); document.write( "

Algebra.Com's Answer #238701 by jrfrunner(365) $\"\"$ $\"About$

You can put this solution on YOUR website!
let x=number of balls whose number is >= 17
\n" ); document.write( "--
\n" ); document.write( "we want
\n" ); document.write( "in a sample without replacement
\n" ); document.write( "P(X>=1) = 1-P(x=0) (Getting at least one is the same as the complement of getting none)
\n" ); document.write( "---
\n" ); document.write( "P(x=0)=P(all 3 are numbered <17) = $\"%2816%2F20%29%2A%2815%2F19%29%2A%2814%2F18%29=0.491\"$
\n" ); document.write( "P(X>=1)=1-0.491=0.509
\n" ); document.write( "===
\n" ); document.write( "This could also be solved as
\n" ); document.write( " $\"1-+16C3%2A4C0%2F20C3++\"$ \n" ); document.write( "

\n" );