Helena invests a sum of money into an account that pays 6% compound interest per annum. Work out after how many years Helena will have trebled his investment. Give your answer as a whole number of years.

This is what i found “an explicit formula designates the nth term of the sequence, as an expression of n (where n = the term's location). it defines the sequence as a formula in terms of n. this example is an arithmetic sequence(the same number, 5, is added to each term to get to the next term).” i hope this you for what your looking for. can you plz mark me brainliest?