志聪（Zhi Cong）每2分钟可以打90个字。他往往每10分钟会打错9个字。

它不会直接告诉你答案，而是问你卡在哪一步看看 AI 是怎么陪你一步步弄懂这道题的

完整解法

1. Convert the total time to minutes

$2 \text{ hours} = 2 \times 60 = 120 \text{ minutes}$

2. Calculate the total number of words typed in 120 minutes

Number of 2-minute intervals $= \frac{120}{2} = 60$
Total words $= 60 \times 90 = 5400$

答案

$5400$

1. Calculate the total number of incorrect words typed in 2 hours

Number of 10-minute intervals in 2 hours (120 minutes) = $120 \div 10 = 12$
Incorrect words = $12 \times 9 = 108$

2. Calculate the total number of correct words

Total words typed in 2 hours = $5400$ (from part a)
Correct words = $5400 - 108 = 5292$

答案

$5292$

AI 分析，可能出错

用 AI 批改，圈出写错的那一步，并自动将你的薄弱点存入错题本，形成你的错因库。