To find simple interest:
Time = Interest/(Principle)(Rate)
Interest is the amount of interest paid
Principle is the amount you lent or borrow
Rate is the percentage of principle charged as interest each year
Time is the years of the loan
P=Principle amount of $1,500
I=Interest amount of $1,200 (Take the new amount of $2,700 and subtract from the principle that is $1,500 which gives you $1,200)
r= as a decimal .15 (15%/100)
t=unknown
T=I/PR
T=1,200/(1,500)(.15)
T=1,200/225
T=5.3 years
It would take Lance roughly 5.3 years