There are several apples, give (1/3) of them to A, distribute the remaining (1/5) 3 less apples to B, and then give all the remaining apples to C, so that C gets more apples than The number of apples obtained by A is 21 more. How many apples are there in total?
有苹果若干个，把其中的(1/3)给A，把余下的(1/5)少3个的苹果分给B，再把剩下的全部苹果都给C，这样C得到的苹果比A得到的苹果数多21个，问共有多少个苹果？
<gadget id="calculator">21 - 3</gadget>
<output>18</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(2/3) * (4/5)</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">(8/15) - (1/3)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">18 / (1/5)</gadget>
<output>90</output>

<result>90</result>