A family made three trips to the grocery store in one month.

* On the first trip, they spent $100 on groceries.

* On the second trip, they spent 20% less than they did on the first trip.

* On the third day, they spent [tex]\frac{3}{4}[/tex] as much as they did on the second trip.

What was the total amount of money the family spent on groceries for the month?