Seven of the 10 children at art camp make an average of 8 paintings. the remaining children make an average of 12 paintings. what is the average number of paintings made by children at the art camp? plzz

Mustafa contributes 11% of his $67,200 annual salary to his 401k plan. what is his pretax income

Imogene invested $8,000 in a bank account that pays 8 percent simple interest at the end of each year. her friend invested the same amount in stocks where the growth of the investment is represented as 2,000 times the square root of 2 less than the time lapsed in years. if y1 and y2 represent the amount earned in dollars and t is the time lapsed in years, which system of equations correctly represents the situation?

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.