Does anyone know what this equation is? i'm pretty sure the first part is surface area

Student price tickets to a movie are $1 and non student tickets are $2 . 350 tickets are sold and the total amount made is $450. there were 250 student tickets sold . true or false .

Find the domain of the following expression: 1/(√x)-2

Consider a cube that has sides of length l. now consider putting the largest sphere you can inside this cube without any point on the sphere lying outside of the cube. the volume ratio -volume of the sphere/ volume of the cube is 1. 5.2 × 10−1 2. 3.8 × 10−1 3. 1.9 4. 2.5 × 10−1 5. 3.8