The elder brother is 105 cm tall, 20 cm taller than the younger brother, and the father is exactly twice the height of the younger brother. How many centimeters is dad's height?
哥哥身高105厘米，比弟弟高20厘米，爸爸的身高正好是弟弟的2倍．爸爸的身高是多少厘米？
<gadget id="calculator">105 - 20</gadget>
<output>85</output>

<gadget id="calculator">85 * 2</gadget>
<output>170</output>

<result>170</result>