The |6f|= -2 i don't understand what to do

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?

You eat $0.85 for every cup of hot chocolate you sell. how many cups do you need to sell to earn $55.25

The ages of personnel in the accounting department of a large company are normally distributed with a standard deviation of 7 years. there is a 0.02275 probability that the age of any randomly chosen person in the department is less than 22 and 0.15866 probabilty that the age of any randomly chosen person is greater than 43. what is the mean of this distribution?