###Human: John's camera broke so he decided to rent one for 4 weeks.  It was a $5000 camera and the rental fee was 10% of the value per week.  His friend who was there when it broke agreed to pay 40% of the rental fee.  How much did John pay?, ### Assistant: The rental fee is 5000*.1=$500 per week
So it cost 500*4=$2000
His friend pays 2000*.4=$800
So he pays 2000-800=$1200 
 So the answer is :  1200