Last year Sarah invested money in two accounts. The first account had an interest rate of 4% and the second account had an interest rate of 3%. If she invested $700 more in the first account than the second and her total interest income was $483, how much did she invest at each rate?

Charles is on a 8 1/2 mile bike ride. he stops for a rest after he’s gone 5 2/5 miles. how much farther does he still have to go?

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?