The school selects the members of the choir from grades three to five. If the fifth grade selects 30, and the fourth and third grades select 5 less, then how many people are there in the chorus?
学校要在三至五年级挑选合唱队队员．如果五年级选了30名，四年级和三年级依次少选5名，那么合唱队一共有多少人？
<gadget id="calculator">30 - 5</gadget>
<output>25</output>

<gadget id="calculator">30 - 5 - 5</gadget>
<output>20</output>

<gadget id="calculator">30 + 25 + 20</gadget>
<output>75</output>

<result>75</result>