In the donation activity of Xinhua Primary School to the disaster area, the amount donated by the middle grades was 250 yuan less than that of the lower grades by 1.5 times, which was 5/6 of the amount donated by the senior grades. It is known that the lower grades donated 3,500 yuan, how much is the senior grade donated?
新华小学在向灾区捐款活动中，中年级捐款数比低年级的1.5倍少250元，是高年级捐款数的(5/6)．已知低年级捐款3500元，高年级捐款多少元？
<gadget id="calculator">3_500 * 1.5</gadget>
<output>5_250</output>

<gadget id="calculator">5_250 - 250</gadget>
<output>5_000</output>

<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">5_000 / (5/6)</gadget>
<output>6_000</output>

<result>6_000</result>