In 10 years, Melanie will be 18 years old. In how many years will her age be thrice her present age?
Melanie's present age is 18 - 10 = 
<gadget id="calculator">18-10</gadget>
<output>8</output>
8.
Thrice Melanie's present age is 8 x 3 = 
<gadget id="calculator">8*3</gadget>
<output>24</output>
24.
So, she will be thrice her present age in 24 - 8 = 16 years.

<result>16</result>