Word problem

Question

in the year 2016, jake has $6,200 in his savings account that earns 4.3% compounded quarterly. if jake opened THE account in 2010 what is the principal? suppose jake opens a second savings account and starts with a principal of $4,000 option A earns 6.1% compounded monthly and option b earns 6.5% compounded bi annually. Which option gives jake more money after exactly 3 years? 

Answer 1

The first question:

6200 = p(1 + 0.043/4)⁴⁽⁶⁾

The second question:

A₁ = 4000(1 + 0.061/12)¹²⁽³⁾

A₂ = 4000(1 + 0.065)³