An old man said: "Add 17 to my age, divide by 4, subtract 15 and multiply by 10, which is exactly 100 years old." How old is this old man?
有一位老人说："把我的年龄加上17，再用4除，再减去15后乘以10，恰好是100岁．"这位老人有多少岁？
<gadget id="calculator">100 / 10</gadget>
<output>10</output>

<gadget id="calculator">10 + 15</gadget>
<output>25</output>

<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">100 - 17</gadget>
<output>83</output>

<result>83</result>