Question

Sangho 把一个视频上传到某网站，观看者可以投喜欢票或不喜欢票。每个视频的初始分数为 $0$ ，每收到一张喜欢票，分数增加 $1$ ；每收到一张不喜欢票，分数减少 $1$ 。

某一时刻，Sangho 看到视频的分数为 $90$ ，而且所有投票中有 $65\%$ 是喜欢票。当时这个视频一共收到了多少票？

Sangho uploaded a video to a website where viewers can vote that they like or dislike a video. Each video begins with a score of $0,$ and the score increases by $1$ for each like vote and decreases by $1$ for each dislike vote.

At one point Sangho saw that his video had a score of $90,$ and that $65\%$ of the votes cast on his video were like votes. How many votes had been cast on Sangho’s video at that point?

$200$

$300$

$400$

$500$

$600$

答案：B

知识点：百分数一次方程

难度评级：900

小提示：

设总票数为 $N$ 。

Let $N$ be the total number of votes

大提示：

分数等于喜欢票数减去不喜欢票数。

The score is likes minus dislikes

解答：

喜欢票占 $65\%$ ，所以不喜欢票占 $35\%$ 。因此视频分数等于总票数的 $65\% - 35\% = 30\%$ 。

已知分数为 $90$ ，所以总票数为 $90 \div 30\% = 300$ 。

因此正确答案是 B。

If $65\%$ of votes were like votes, then $35\%$ of votes are dislike votes. Then Sangho’s score is $65\% - 35\% = 30\%$ the total number of votes.

We know that Sangho’s score is $90,$ so the total number of votes is $90 \div 30\% = 300.$

Thus, B is the correct answer.

2018 AMC 10A 第 6 题

答案：B

难度评级：900

小提示：

大提示：

解答：

其他年份的第 6 题