A, B, and C all use Ruyi cards on their mobile phones, and they have received a discount of one month's basic phone bill, and all three of them have exceeded the basic phone bill. It needs to charge additional phone charges every month. As a result, A paid 70 yuan, B paid 50 yuan, and C paid 30 yuan. The total call time for three people is 90 hours. If these hours are used by one person, 350 yuan is required. How many hours of C's calls this month?
甲乙丙三人的手机都使用了如意卡，并获得了赠送一个月基础话费的优惠，三人均超过了基础话费．需月加收话费，结果甲支付了70元，乙支付了50元，丙支付了30元．三人通话总时为90小时．如果这些时间由一个人通话使用，需支付350元，那么本月丙通话多少小时？
<gadget id="calculator">70 + 50 + 30</gadget>
<output>150</output>

<gadget id="calculator">350 - 150</gadget>
<output>200</output>

<gadget id="calculator">200 / 2</gadget>
<output>100</output>

<gadget id="calculator">100 + 30</gadget>
<output>130</output>

<gadget id="calculator">100 + 70 + 100 + 50 + 130</gadget>
<output>450</output>

<gadget id="calculator">130 / 450</gadget>
<output>13/45 = around 0.288889</output>

<gadget id="calculator">90 * (13/45)</gadget>
<output>26</output>

<result>26</result>