A certain candy store sold lollipops for $0.90 each and pieces of individually wrapped saltwater taffy for $0.20 each. If a customer purchased both lollipops and taffy from the store, and spent a total of $3.90, what total number of lollipops and saltwater taffy did the customer purchase?	Choose the correct answer:
A) 6
B) 7
C) 8
D) 9
E) 10
we can take numbers, as price of lollipop 9, 2 for taffy and 39 total for ease.   Now we can determine quickly that total number should range between 39/9 &lt;= N &lt;=39/2, so ans should be between 4 and 20.   Now solving the expression 9A+2B =39   first possibility with 1 lollipop, 15 taffy we get $3.90 total amount, but   1+15= 
<gadget id="calculator">  1+15</gadget>
<output>16</output>
16, and 16 is not an option.   So next choice, for 9A+2B=39 would come by decreasing 39 in multiple of 9 and checking divisibility of that number by 2. this way we get   3 lollipop, 6 taffy would be $3.90 total, 3*0.90 + 6*0.20= 3.90   Hence total number is  3 + 6= 
<gadget id="calculator"> 3 + 6</gadget>
<output>9</output>
9   Ans 9
<result>D</result>
A certain candy store sold lollipops for $0.90 each and pieces of individually wrapped saltwater taffy for $0.20 each. If a customer purchased both lollipops and taffy from the store, and spent a total of $3.90, what total number of lollipops and saltwater taffy did the customer purchase?