Mary worked from Monday to Saturday last week and bought lunch in the company’s restaurant every day. Her lunches cost a different amount every day. Each lunch cost a multiple of 20¢. The most expensive lunch of the week cost $7.60 and the cheapest one cost $4.40. Friday’s lunch cost exactly 1 1/2 times as much as Wednesday’s lunch. Tuesday’s lunch cost $1.20 more than Thursday’s lunch. (a) What is the minimum total that Mary’s six lunches last week could have cost? * (b) What is the maximum total that Mary’s six lunches last week could have cost?