og11 ds#61

[throne]

how many integers are there between, but not including, integer r and s?

a. s-r =10

b. there are 9 integers between, but not including, r+2 and s+1

ans:d

我不懂第二選項的意思

[小花]

題目打錯了

there are 9 integers between, but not including, r+1and s+1

but not including 應該是插入語

So句子簡化
there are 9 integers between r+1 and s+1
r+1 和 s+1 有九個整數在這兩個數字之間 但不包含這兩個數字
r+1 和 s+1 的距離= r 和s
知道r s 的距離就可知道有多少整數在r,s 之間