On Monday, he received 4 boxes. On Wednesday, he received 11 boxes, so he received 15 boxes altogether.
Aida did not use 0.18 for 18%.
When you are finding the percent of something, you can also do this in the attachment below. Yes it is written on a napkin. Hope I helped.
X= one ride ticket
12x+7=31
-7 -7
12x = 12x
--- ---
12 12
x=2
$2
If you have a value for a variable you plug that value in and see if the resulting answer is true.