First, you would need to find out how much 1 sun visor would cost. To do this, you would divide $90 among the 12 sun visors.
$90 ÷ 12 = $7.50
It costs $7.5 per sun visor.
Next, you would need to create an equation to find out how much it will cost to buy 15 more sun visors.
($7.50 × 15) + $90 = $202.50
It will cost $202.50 in total to buy 12 visors plus another 15.
Now, the last thing you would need to do is calculate how much it would cost to buy 16 sun visors.
$7.50 × 16 = $120
It would cost $120 to buy 16 sun visors.
I hope this helps!