Four more than three times n equals -5

Divide. write in the simplest form. 4 1/6 divided by 10

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

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?