阿米娜女士烤了一些饼干来卖。其中 $\frac{3}{4}$ 是奶油饼干，其余的是原味饼干。在卖掉 210 个原味饼干和 $\frac{5}{6}$ 的奶油饼干后，她还剩下全部饼干的 $\frac{1}{5}$ 。阿米娜女士一共卖掉了多少个饼干？答: ___

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. Find the fraction of the total cookies that were cream cookies sold.

Fraction of cream cookies sold = $\frac{5}{6} \times \frac{3}{4} = \frac{5}{8}$

2. Find the fraction of the total cookies that corresponds to the plain cookies sold.

Fraction of plain cookies sold = $1 - \frac{5}{8} - \frac{1}{5} = \frac{40}{40} - \frac{25}{40} - \frac{8}{40} = \frac{7}{40}$

3. Calculate the total number of cookies baked.

$\frac{7}{40}$ of total cookies = $210$
Total cookies = $210 \div 7 \times 40 = 1200$

4. Calculate the total number of cookies sold.

Fraction of cookies sold = $1 - \frac{1}{5} = \frac{4}{5}$
Total cookies sold = $\frac{4}{5} \times 1200 = 960$

答案

$960$

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