A shop sells two variants of chocolates - one that costs $3 and the other that costs $5. If the shop sold $121 chocolates on a given day, how many different combinations of (number of $3 sold, number of $5 sold) exist? Options:
A) 4  B) 6  C) 8  D) 10  E) 12
$121 = 23*$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 23, 20, 17, 14,...,2 for a total of 8 combinations.   The answer is 8.
<result>C</result>
A shop sells two variants of chocolates - one that costs $3 and the other that costs $5. If the shop sold $121 chocolates on a given day, how many different combinations of (number of $3 sold, number of $5 sold) exist?