Hey Mona,
The thing is that all the method in the same call stack should either declare it that it throws the exception or else handle it using try/catch. I know its a bit confusing at the first look towards exception. But this is the best way i can explain it to you. i too got confused on this one and even decided to leave the exception part itself

. But then I read it about 10 times the whole exception part and then i was clear with this one. And then i successfully went thru the exam scoring wid a huge margin. I would say reading the un-understandable stuff agn and agn is the best way to know the stuff.
I hope this helps you.
Kind Regards,
Anish Doshi.