The school launched a donation activity for Hope Primary School. The middle grades donated 350 yuan, accounting for 40% of the total donations of the whole school, and the senior grades donated 35% of the total donations of the whole school. How much did the senior grades donate?
学校开展为希望小学捐款活动，中年级捐了350元，占全校学生捐款总数的40%，高年级捐的钱数是全校捐款总数的35%，高年级捐了多少钱？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">350 / (2/5)</gadget>
<output>875</output>

<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">875 * (7/20)</gadget>
<output>1_225/4 = around 306.25</output>

<result>1_225/4 = around 306.25</result>