Oliver's grandfather invested $150 at 5% interest compounded quarterly. When Oliver inherited it, the amount was $6000. For how many years had the $150 been invested

Question

anonymous · Answer

P = N(1+i)^n I believe is the formula.

anonymous · Answer

no it's A=P[1+(r/n)]^ny

anonymous · Answer

Yea same thing. 
Sub your givens into the formula. Isolate and solve for t.

campbell_st · Answer

is the interest 5% per quarter or 5% per annum...?

anonymous · Answer

quarter

campbell_st · Answer

ok then its

6000 = 150(1+0.05)^n 

divide both sides by 150

40 = 1.05^n 

take the log of both sides

log(40) = nlog(1.05)

n = log(40)/log(1.05) 

n = 75.607

divide by 4 you get the number of years