Summarizing the question, Principle(P)=$100 Rate (r)=12%=0.12 Amount (A)=3×P=$300 Time=t=? n=no of times the interest is compouned per year=4 Then, A=P{(1+r/n)}^(n×t) or,300=100×{1+0.12/4}^(4×t) or,300/100=(1+0.03)^(4×t) or,3=1.03^(4×t) Taking log on both sides, log3=log[(1.03)^(4×t)] or,log3= (4×t)×log(1.03) or,4t=log3/log(1.03) or,t=log3/[4×log(1.03)] or, t=9.29175... t=9.3 years ANS!!!
