Xiao Ming's weight is 42 kg, his cousin's weight is half of his, and his grandfather's weight is three times that of his cousin's. How many kilograms does grandpa weigh?
小明体重42千克，表弟体重是他的一半，而爷爷体重是表弟的3倍．爷爷体重是多少千克？
<gadget id="calculator">42 / 2</gadget>
<output>21</output>

<gadget id="calculator">21 * 3</gadget>
<output>63</output>

<result>63</result>