Each person in a certain household consumes 0.2 kg of rice every meal. Supposing 5 members of the household eat rice every lunch and dinner, how many weeks will a 42 kg bag of rice last?
Each person eats 0.2 kg/meal x 2 meals/day = 
<gadget id="calculator">0.2*2</gadget>
<output>0.4</output>
0.4 kg of rice per day.
So, the 5 members consume 0.4 kg/day/person x 5 people = 
<gadget id="calculator">0.4*5</gadget>
<output>2</output>
2 kg of rice per day.
In a week, the household consumes 2 kg/day x 7 days/week = 
<gadget id="calculator">2*7</gadget>
<output>14</output>
14kg of rice.
Thus, 42 kg of rice will last 42 kg / 14 kg/week = 
<gadget id="calculator">42/14</gadget>
<output>3</output>
3 weeks.

<result>3</result>