How many Kilobytes are in 1 Megabyte?
1 Byte = 8 Bit
1 Kilobyte = 1,024 Bytes
1 Megabyte = 1,048,576 Bytes or 1,024 Kilobytes
In order to answer the question correctly, you have to remember it anyway. The knowledge is no use for ordinary people but every programmer remembers this data by heart!
More Info:
en.wikipedia.org