Of the people in Kurt's apartment building, 10 have a jacket with a hood and 10 have a jacket with buttons. 6 people have a jacket with both a hood and buttons. How many people have a jacket with a hood or buttons or both?

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.