What is the domain and range for y=3×-1

Which fraction below is equivalent to 10/12?

Aschool puts on a play. the play costs $1,200 in expenses. the students charge $4.00 for tickets. there will be one performance of the play in an auditorium that seats 500 people. what is the domain of the function that shows the profit as a function of the number of tickets sold?  

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup