Mark builds an apartment that is 16 by 10 feet.  There are 6 rooms in total.  All the rooms are the same size except the living room which is as big as 3 other rooms.  How big is the living room?
Total square footage is 16*10=
<gadget id="calculator">16*10</gadget>
<output>160</output>
160 square feet.

There are 3+3=
<gadget id="calculator">3+3</gadget>
<output>6</output>
6 rooms
6-1=
<gadget id="calculator">6-1</gadget>
<output>5</output>
5 of them are the same size.
If x is the size of the normal room then the square footage of all rooms is 5x+3x=8x.
So each room is 160/8=
<gadget id="calculator">160/8</gadget>
<output>20</output>
20 square feet.
So the living room is 20*3=
<gadget id="calculator">20*3</gadget>
<output>60</output>
60 square feet.

<result>60</result>