Alunch in a fancy restaurant is three times as expensive as a lunch in a cafeeria. the lunch in the fancy restaurant costs 36. in five day workweek mary eats at the fancy restaurant once and in the cafeteria the rest of the days. how much does she spend on lunches in that week

In this item, we first solve for the cost of eating in a cafeteria. From the given it is stated that the cost of eating in a fancy restaurant is 3 times the cost of eating in cafeteria. Mathematically,

    3x = 36

where x is the cost of eating in cafeteria. 

The value of x from the equation is 12.

In a five-day workweek, she eats at the fancy restaurant once and four times in cafeteria. To determine the total cost,

    T = 4(12) + 36
    
     T = 84

Thus, the answer to this item is 84.