This year, my grandfather is 6 times as old as Xiaoming. After a few years, my grandfather will be 5 times as old as Xiaoming. After a few years, my grandfather will be 4 times as old as Xiaoming. Ask grandpa how old he is this year.
今年祖父的年龄是小明的6倍，几年后，祖父的年龄将是小明的5倍，又过几年以后，祖父的年龄是小明年龄的4倍．问祖父今年多少岁．
<gadget id="calculator">5 * 4 * 3</gadget>
<output>60</output>

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">60 / 5</gadget>
<output>12</output>

<gadget id="calculator">12 + 60</gadget>
<output>72</output>

<result>72</result>