Hey next time use your calculator, if you can.
Since these problems are using this equation : [tex]A(mount) = P(rinciple) * ( 1 + R(ate) ^ {t(ime)} )[/tex] we can derive into this immediately.
Q1: 525 (Try it, don't copy, it's not nice ;) ).
Q2: 865.28
Q3: By using logs: 0.0566 years. (I'm not sure on that one...) Sry