An athletic director pays $90 for 12 sun visors for the softball team. how much will the athletic director pay to buy 15 more sun visors? what is the cost of 16 sun visors?

 he will pay 112.50 for just the 15 more sun visors (not including the 12 he already bought), for 16 he'd pay $120. 

to figure this out you find out how much just one sun visor is so you divide the $90 by 12 sun visors and get 7.50, then you times 7.50 by 15 to get the cost of buying 15 sun visors, same scenario with 16 sun visors... hope this helps.