A cell phone company charges a monthly rate of $12.95 and $0.25 a minute per call. The bill for this month is $21.20. How many minutes were spent on calls?

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

Using pert, adam munson was able to determine that the expected project completion time for the construction of a pleasure yacht is 21 months, and the project variance is 4. a) what is the probability that the project will be completed in 17 months? b) what is the probability that the project will be completed in 20 months? c) what is the probability that the project will be completed in 23 months? d) what is the probability that the project will be completed in 25 months? e) what is the due date that yields a 95% chance of completion?