Fraction form of the unit fraction: 1/13 + 1/13 + 1/13 + 1/13 + 1/13 + 1/13 + 1/13 + 1/13

Assume that the weights of quarters are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. a vending machine will only accept coins weighing between 5.48 g and 5.82 g. what percentage of legal quarters will be rejected? round your answer to two decimal places.

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Apatient is to be given 35 milligrams of demerol every 4 hours. you have demerol 50 milligrams/milliliter in stock. how many milliliters should be given per dose?