Rick deposited $750 to his bank account using $5 and $15 dollar bills only. If Rick came to the bank with 70 bills and left with 10 bills only, how many $15 dollar billsმ did he deposit? Choices
A) 5.
B) 45.
C) 50.
D) 55.
E) 65.
5x+15y=750 --1   x+y=60 ---2   multiply eq 2 with 5 and subtract from eq 1   5x+15y=750   5x+5y=300   10y= 450   y=45 and x = 15   therefore $15 bills = 45   Answer 45.
<result>B</result>
Rick deposited $750 to his bank account using $5 and $15 dollar bills only. If Rick came to the bank with 70 bills and left with 10 bills only, how many $15 dollar billsმ did he deposit?