pp3上一道数学题目,读不懂!

newasers

A store currently charges the same price for each towel that it sells. If the current price of each towel were to be ncreased by $1,10 fewer of the towels could be bought for $120. excluding sales tax. What is the current price of each towel? A $1 B $2 C $3 D $4 E $12 这题目是什么意思啊?实在读不明白!

casualwark11

一个商店以相同的价格卖碗。如果每个碗目前的价格增加10￥，那么会少买10个碗，共花了120￥，不含购买税。　问每个碗目前的价格。

newasers

答案是C,怎么算出来的呢?另外,题目是增加$1啊。

woodruff1

设current price 为x,卖了y for 120$ 由题意 xy=120 (x+1)(y-10)=120 解得x=3