Please help me with this

Will used 20 colored tiles to make a design in art class. 5/20 of his tiles were red. what is an equivalent fraction for the red tiles?

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.

Ineed big ! the cost of a school banquet is $25 plus $15 for each person attending. create a table, sketch the graph, and write an equation in slope-intercept and point-slope form that gives total cost as a function of the number of people attending. what is the cost for 77 people?