Hi Lajwanti http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif
You won't get an answer to a maths question in this New Members Introduction forum---as the name implies, this is just for introducing yourself and saying Hi.
The forums where you can ask for help with homework can be found on our home page, but when you post there you are required to show your attempt at solving the problem. Since you don't know how to start, I think your best resource is your fellow student. Ask someone in your class to explain to you what the question is asking, then make an attempt at solving it through your own effort. If you run into trouble, ask for help with the next step on our forums.
That is the most effective and productive way to make use of this PF homework help resource.