Answer:
He does not have enough money to buy the hat.
Step-by-step explanation:
First find out how much he spent on the ticket:
![90 \times {31 \over 45}=2 \times 31=62](https://tex.z-dn.net/?f=90%20%5Ctimes%20%7B31%20%5Cover%2045%7D%3D2%20%5Ctimes%2031%3D62)
He spent $62 on the ticket, so he has $90 - $62 = $28 remaining. Now find out how much of that he spent at the concession stand:
![28 \times {3 \over 7}=4 \times 3=12](https://tex.z-dn.net/?f=28%20%5Ctimes%20%7B3%20%5Cover%207%7D%3D4%20%5Ctimes%203%3D12)
He spent $12 at the concession stand, so he has $28 - $12 = $16 remaining. He does not have enough to buy the $18 hat.