document.write( "Question 1090359: 7. Frank bought supplies for school. In the first store, he spent half of his money plus $10. In the second store, he spent half of what he had left, plus $10. In the third store, he spent 80% of what he had left. He came home with $5. How much did he start out with? \n" ); document.write( "
Algebra.Com's Answer #704825 by jorel1380(3719)![]() ![]() You can put this solution on YOUR website! Let n be the amount Frank started with. Then, after each store, he would have: \n" ); document.write( "1st store:n/2 -10 \n" ); document.write( "2nd store:1/2(n/2 -10) -10 \n" ); document.write( "3rd store:.2((1/2(n/2 -10) -10)) \n" ); document.write( "So: .2((1/2((n/2 -10) -10))=5 \n" ); document.write( "Then, solve for n \n" ); document.write( "You can also work backwards. For example, Frank ends with $5. Since, in the third store, he spent 80% of what he had left after the second store, he would have 5/.2, or $25. Then, add $10 and multiply by 2 to get $70, etc.. \n" ); document.write( "☺☺☺☺ \n" ); document.write( " |