Question 985316
<pre>
Michelle, at present, is 3 times as old as her daughter. 

M = 3D

In 10 years' time she [Michelle] wil be twice her daughter's age. 

In 10 years' time she [Michelle] will be M+10
In 10 years' time the daughter will be D+10

So

M+10 = 2(D+10)

To get the answer, solve this system of equations by substitution:

{{{system(M=3*D,M+10=2(D+10))}}}

Edwin</pre>