Subnet Address

I have taken following question from a book (CCNA course book). I didn't understand what the question and what will be the answer. Can any one help me understanding the question???

Given a Class B Network with subnet mask of 255.255.248.0 and a packet addressed to 130.40.32.16, what is the subnet address?

The answer should be 130.40.32.0

The subnet address in the IP address with the network address and without host bits. To find it we do an AND operation between the IP address and the subnet mask.

Converting 130.40.32.16 to binary:

10000010.00101000.00100000.00010000

Converting the subnet mask 255.255.248.0 to binary:

11111111.11111111.11111000.00000000

ANDing the two binaries we get:

10000010.00101000.00100000.00000000

Back to decimal we get: 130.40.32.0

Thanks Solo.

The question was so simple and sill I didn't understand it.