You decide to put $150 in a savings account to save for a $3,000 down payment on a new car. if the account has an interest rate of 2.5% per year and is compounded monthly, how long does it take you to earn $3000 without depositing any additional funds

(Look at the attached graphic)
Years = log (3,000 / 150) / 12 * log (1 + .025 / 12)
Years = log (20) / 12 * log ( 1.0020833333 )
Years = 1.3010299957 / 12 * .0009038389838
Years = 1.3010299957 / 0.0108460678
Years = 119.954
That's a LONG time
 

It is going to be the third choice

Using the rise/run rule. you would get 2/6.simp. 1/3