Wally purchased a bag of marbles on monday. on tuesday he gave half of the marbles to his brother, james. on wednesday he gave ten marbles to his sister. on thursday he gave twenty marbles to his other sister. wally had fifty marbles left. how many marbles did wally purchase on monday?

Amanda went into the grocery business starting with five stores. after one year, she opened two more stores. after two years, she opened two more stores than the previous year. if amanda expands her grocery business following the same pattern, which of the following graphs represents the number of stores she will own over time?