SAT Mathematics Practice Test 6

The total amount T, in dollars, Salim will pay for n tickets is given by $\mathit{T}=15\mathit{n}+12,$ which consists of both a per-ticket charge and a one-time service fee. Since n represents the number of tickets that Salim purchases, it follows that $15\mathit{n}$ represents the price, in dollars, of n tickets. Therefore, $15$ must represent the per-ticket charge. At the same time, no matter how many tickets Salim purchases, he will be charged the 12 dollars fee only once. Therefore, $12$ must represent the amount of the service fee, in dollars.
Choice A is incorrect. Since n represents the total number of tickets that Salim purchases, it follows that $15\mathit{n}$ represents the price, in dollars, of n tickets, excluding the service fee.Therefore, 15, not $12,$ must represent the price of $1$ ticket. Choice C is incorrect. If Salim purchases only 1 ticket, the total amount, in dollars, Salim will pay can be found by substituting$\mathit{n}=1$ into the equation for $\mathit{T}.$ If $\mathit{n}=1,\mathit{T}=15\left(1\right)+12=27.$ Therefore, the total amount Salim will pay for one ticket is $27,\mathit{n}\mathit{o}\mathit{t}$12. Choice D is incorrect. The total amount, in dollars, Salim will pay for n tickets is given by $15\mathit{n}+12.$ The value 12 represents only a portion of this total amount. Therefore, the value 12 does not represent the total amount, in dollars, for any number of tickets.