While reading in bed with his wife Susan, Charlie heard a noise at the door. It was Sarah entering the bedroom with 4 friends. If there were also 8 people in the living room, how many people are in the house?
In the bedroom, there are 1 + 1 = 
<gadget id="calculator">1+1</gadget>
<output>2</output>
2 people in the house (Charlie and Susan).
Sarah and four friends then entered, a total of 4+1 = 
<gadget id="calculator">4+1</gadget>
<output>5</output>
5 people.
Together with Charlie and Susan, there are now 5+2 = 
<gadget id="calculator">5+2</gadget>
<output>7</output>
7 people in the bedroom.
Since there are 8 more people in the living room, the total number of people in the house is 8 + 7 = 
<gadget id="calculator">8+7</gadget>
<output>15</output>
15.

<result>15</result>