The circumference of a circle equals 30 pai what is the diameter radius and the arc length of a 270° arc

Ivan and jeff buy a package of 8 pens for $4.00. ivan wants 5 of the pens, and jeff wants 3.how much should each student pay?

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Nick has box brads. he uses 4 brads for the first project. nick let’s b represent the original number of brads and finds that for the second project, the number of brads he uses is 8 more than half the difference of b and 4. write an expression to represent the number of brads he uses for the second project.