Andrew has $40. He wants to buy a $15 cd and as many $6 posters as he can. What is the greatest number of posters he can buy?

I did 40>or=15+6x
-15 to each side
25/6> or=6x/6
4.17> or = x so he can buy 4 at most
Is this correct?
Thanks

( 40 - 15 ) / 6 = 25 / 6 = 4.166

4 posters

Total cost :

15 + 4 * 6 = 15 + 24 = 39 $