How many mb in 1.60 gb?

I'm assuming you are referring to Bytes so...1638.4 MegaBytes in 1.60 GigaBytes, although you put the abbreviations in lowercase which usually indicates Bits instead of Bytes so just in case...

1.6 GigaBytes = 13107.2 megabits
1.6 gigabits = 1638.4 megabits
1.6 gigabits = 204.8 MegaBytes