If $70000 is invested at 5% compounded quarterly, how long will it take for the investment to triple in value?

Question

need to know how many years it will take to triple in value. 

Answer 1

A = P(1 + r/n)^nt

210,000 = 70000(1 + .05/4)^4t

3 = (1.0125)^4t      Change to log form

log_1.01253 = 4t    Use the change of base formula

log3/log1.1025 = 4t

11.25854 = 4t

2.8 years = t