Question 1026035
current age=x
x+10+20=3x, in 10 years she will be 20 years younger than 3 times her current age.  So add 20 to x+10, her age in 10 years.
x+30=3x
30=2x
x=15
She is 15.
In 10 years, she will be 25, and that is 20 years younger than 3*15, which is 45.