I was asking for a clarification.
My question was not Homework type.
I had worked out a solution myself.
In your question, what you actually ask is
...is my answer right? or is there a mistake in the calculation. Kindly discuss.
Asking whether your answer is right is not on topic here. That's why it was put on hold.
If you focus your question more on why you think your answer might not be right, that would be a good start toward writing a better question for this site (and perhaps getting it taken off hold).