The three brothers donated to the disaster area, the eldest donated from the other two (2/3), the second donated from the other two (3/5), the eldest donated 90 yuan, how much did the three brothers donate in total? ?
兄弟三人向灾区捐款，老大捐的是另外两人捐款的(2/3)，老二捐的是另外两人的(3/5)，老大捐了90元，三兄弟一共捐了多少元？
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">90 / (1/2)</gadget>
<output>180</output>

<result>180</result>