Question $6\mathrm{.}10$

To accumulate $36,419\mathrm{.}74$ at the end of $3n$ years, deposits of $174$ are made at the end of

the first $n$ years, and deposits of $87$ are made at the end of each of the next $2n$ years.

The annual effective interest rate is $i,$ and you are given that:

$(1+i{)}^n=3$

Calculate $i.$

A $7\mathrm{.}64\%$

B $10\mathrm{.}51\%$

C $10\mathrm{.}75\%$

D $14\mathrm{.}81\%$

E $15\mathrm{.}05\%$