document.write( "Question 412530: how many 4-digit pins are possible if the first digit may not be a zero, and one of the digits may be repeated? \n" ); document.write( "
Algebra.Com's Answer #289751 by Alan3354(69443)\"\" \"About 
You can put this solution on YOUR website!
9*10*10*10 if you mean any digit can be repeated.
\n" ); document.write( "If one of them, and not the others, can be repeated, you'll have to clarify that.
\n" ); document.write( "= 9000 PINs
\n" ); document.write( "
\n" ); document.write( "
\n" );