What are the operations for inverces

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?

Suppose sat writing scores are normally distributed with a mean of 497 and a standard deviation of 109. a university plans to award scholarships to students whose scores are in the top 2%. what is the minimum score required for the scholarship? round your answer to the nearest whole number, if necessary.

Adoctor administers a drug to a 38-kg patient, using a dosage formula of 50 mg/kg/day. assume that the drug is available in a 100 mg per 5 ml suspension or in 500 mg tablets. a. how many tablets should a 38-kg patient take every four hours? b. the suspension with a drop factor of 10 ggt/ml delivers the drug intravenously to the patient over a twelve-hour period. what flow rate should be used in units of ggt/hr? a. the patient should take nothing pills every four hours. (type an integer or decimal rounded to the nearest hundredth as needed.)