document.write( "Question 1070580: 80% of the red hat society is over 65 years old. 80% of those over 65 years old are also over 75 years old. How many members are over 75 years old if 240 members are between 65 and 75 years old? \n" ); document.write( "

Algebra.Com's Answer #685644 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+x+\"$ = total members of the red hat society
\n" ); document.write( " $\"+.8x+\"$ = those over 65 yrs old
\n" ); document.write( " $\"+.8%2A%28+.8x+%29+=+.64x+\"$ = those over 75 yrs old
\n" ); document.write( "-----------------------------------------------
\n" ); document.write( "given:
\n" ); document.write( " $\"+.8x+-+.64x+=+240+\"$
\n" ); document.write( " $\"+.16x+=+240+\"$
\n" ); document.write( " $\"+x+=+1500+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+.64x+=+.64%2A1500+\"$
\n" ); document.write( " $\"+.64x+=+960+\"$
\n" ); document.write( "-----------------------
\n" ); document.write( "960 members are over 75
\n" ); document.write( "-----------------------
\n" ); document.write( "check:
\n" ); document.write( "Those under 65:
\n" ); document.write( " $\"+x+-+.8x+=+.2x+\"$
\n" ); document.write( " $\"+.2x+=+.2%2A1500+\"$
\n" ); document.write( " $\"+.2x+=+300+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "Those 65 - 75:
\n" ); document.write( " $\"+.8x+-+.64x+=+.16x+\"$
\n" ); document.write( " $\"+.16x+=+.16%2A1500+\"$
\n" ); document.write( " $\"+.16x+=+240+\"$
\n" ); document.write( "----------------------
\n" ); document.write( "Those over 75:
\n" ); document.write( " $\"+.8%2A%28+.8x+%29+=+.64x+\"$
\n" ); document.write( " $\"+.64x+=+.64%2A1500+\"$
\n" ); document.write( " $\"+.64x+=+960+\"$
\n" ); document.write( "----------------------
\n" ); document.write( " $\"+300+%2B+240+%2B+960+=+1500+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

\n" );