Which of these is a unit rate? a. $3.50 for 2 gallons of juice b. $5.00 for 3 pounds of cheese c. $4.25 for 1 watermelon d. $2.75 for 6 hamburger rolls

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible

Someone me i need with this stuff

Use sigma notation to represent the following series for 9 terms.