Question 393971
12,000(1+r)^(2)= 27000
so it's just an equation, solve it like one
start by dividing both sides by 12,000
(1+r)^2 = 2.25
Now get rid of that ugly square , the opposite of squaring a number, is square root, so root both sides
1 + r = 1.5
r = .5
so the multiplier would be 1.5 , which means he gained 50% a year

Hope i helped