有一個問題 問了補習班的班導,結果還是爬不出來
請問
An agent was billed a total of $6.00 for n reams of paper. As a result of a price increase of $0.25 per ream, the agent’s next bill of $6.00 was for 4 fewer reams of paper. The second bill was for how many reams of paper?
(1)8
(2)12
(3)24
(4)25
(5)48
答案是(1),但是我自己怎麼算都是12

原價是(6/n)元,但價格每令上升0.25,所以新價格是(6/n)+0.25元
第二次的帳單一樣是$6.00元,但是少了四張,所以是(n-4)張
所以方式式是
[(6/n)+0.25]*(n-4)=6
n=-8 or 12
請各位幫忙一下 謝謝
Amy Liang