There are 150 students in 3 classes in the first grade of the school, and the number of students in each class is equal. It is known that the number of boys in Class 1 is equal to the number of girls in Class 2, and the number of boys in Class 3 is 1/5 of the total number of students in the whole grade. How many boys are there in Grade 1?
学校一年级3个班共有150人，每个班人数相等．已知一班的男生人数与二班的女生人数相等，三班的男生是全年级总人数的(1/5)，一年级共有男生多少人．
<gadget id="calculator">150 / 3</gadget>
<output>50</output>

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

<gadget id="calculator">150 * (1/5)</gadget>
<output>30</output>

<gadget id="calculator">50 + 30</gadget>
<output>80</output>

<result>80</result>