Question

If books are $3 books and comics $1 each , what are the possible final costs ? select all that apply

Answer 1

The possible total costs are $54, $72 and $90

Here, we want to get the final possible costs

The ratio of the costs are; book to comics are 5 to 3

Hence, for every 5 books, 3 comics are bought

Thus, we have it that;

The cost 5(3) + 3(1) = 15 + 3 = 18

So, the possible total costs are multiples of 18

The multiples are 54, 72 and 90