There are three classes in the sixth grade. Classes Six 1 and Class Six 2 account for 5/7 of the total number of students in the whole grade. Classes Six 1 and Class Six 3 account for 2/3 of the total number of students in the whole grade. , how many people are there in the whole grade?
六年级有三个班，六1班与六2班人数占全年级人数的(5/7)，六1班与六3班人数占全年级人数的(2/3)，六1班有40人，全年级有多少人？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 - (5/7)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(2/3) - (2/7)</gadget>
<output>8/21 = around 0.380952</output>

<gadget id="calculator">40 / (8/21)</gadget>
<output>105</output>

<result>105</result>