A shop sells two variants of chocolates - one that costs $3 and the other that costs $5. If the shop sold $141 chocolates on a given day, how many different combinations of (number of $3 sold, number of $5 sold) exist? Choose the correct choice from the following answers.
A) 5
B) 7
C) 9
D) 11
E) 13
$141 = 27*$5 + 2*$3   We can find other combinations by reducing the $5 chocolates by 3 (which is -$15)and increasing the $3 chocolates by 5 (which is +$15).   The number of $5 chocolates can be 27, 24, 21, 18, 15,...,3 for a total of 9 combinations.   The answer is 9.
<result>C</result>
A shop sells two variants of chocolates - one that costs $3 and the other that costs $5. If the shop sold $141 chocolates on a given day, how many different combinations of (number of $3 sold, number of $5 sold) exist?