Please someone answer this question!?

Question

A ferry has a deck area of 3600m square, for parking cars and trucks. Each car takes up 20m square of deck area and each truck takes up 80m square. On one trip, the ferry carries x cars and y Trucks.

Show that this information leads to the inequality x+4y less than or equal to 180

Answer 1

The ferry can only carry as many vehicles as will fit on its deck. So, the total area needed by the vehicles must be less than or equal to the deck area.

There are x cars, so they take up 20 x square meters.
There are y trucks, so they take up 80 y square meters.
The total deck area is 3600 square meters.

Now make an inequality from that:
20 x + 80 y <= 3600

Now divide each term by 20, to "reduce" the inequality to lowest terms:
x + 4 y <= 180