Master Wang bought a barrel of gasoline, and after using it twice, there was still 28 liters left. It is known that 30% was used the first time, and 35 liters were used the second time. How many liters is this barrel of gasoline?
王师傅买来一桶汽油，用了两次以后还剩下28升，已知第一次用去了30%，第二次用去了35升．这桶汽油原有多少升？
<gadget id="calculator">35 + 28</gadget>
<output>63</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">63 / (7/10)</gadget>
<output>90</output>

<result>90</result>