PLZZZ JUST HELPPP Fwam has a smart phone data plan that costs $20 per month that includes 6 GB of data, but will charge an extra $10 per GB over the included amount. How much would Fwam have to pay in a month where he used 3 GB over the limit? How much would Fwam have to pay in a month where he used went over by x GB?

Cost when over by 3 GB: ?
Cost when over by x GB:?

Can someone check my answer? you : )

Jeffery conducted a survey in his school and found that 30 of the 50 eighth grade students' favorite subject is mathematics. based on the results, jeffery concluded that out of the 200 students in his school, 120 students' favorite subject is mathematics. select the statement that is true about jeffery's conclusion. a. jeffery's conclusion is not valid because the sample was biased since only 200 students were surveyed. b. jeffery's conclusion is valid because the sample was random since all of the students were eighth grade students. c. jeffery's conclusion is valid because the sample was random. d. jeffery's conclusion is not valid because the sample was biased since all of the students were eighth grade students.

For how answer my question this will be the last question can you answer in math subject