Question 1160255
I = x
A = 3x
After 10 years
I = x+10 
A = 2(x+10) = 2x+20
(x+3x)+10 = (x+10+2x+20)
4x+10 = 3x+30
x = 20
3x = 60
Check-----
(x+3x)+10 = (x+10+2x+20)
90 = 90