OG详解-OG3 数学1 Q3

Choice C is correct. It’s given that the cost of renting a tent is  $11 per day for d days. Multiplying the rental cost by the number of days yields  $11d, which represents the cost of renting the tent for  d  days before the insurance is added. Adding the onetime insurance fee of  $10 to the rental cost of  $11d  gives thetotal cost c , in dollars, which can be represented by the equation  c = 11d +10 .
Choice A is incorrect. This equation represents the total cost to rent the tent if the insurance fee was charged everyday. Choice B is incorrect. This equation  represents the total cost to rent the tent if the daily fee was $(d +11) for 10 days. Choice D is incorrect. This equation represents the total cost to rent the  tent if the daily fee was $10  and the onetime fee was $11.