I have completed the following question, but not sure if it is correct.

1. Sarina is saving for her ovseas trip to Los Angeles and needs to save $540 in 3 months. What amount of money must she invest at 9% p.a. in order to earn this amount?

I= Prn

540= P x 0.09 x 0.25

540/0.225 = 2400

Therefore, Sarina must invest $2400 in order to earn this amount.