Step-by-step explanation:
now, are we doing the formal informatical calculation, where we are always going with powers of 2, or with the cheating (by the manufacturers of flash drives) approach ?
regularly we go with 2¹⁰ = 1024 :
1 KB = 1024 Bytes
1 MB = 1024 KB
1 GB = 1024 MB
1 TB = 1024 GB
...
the manufacturer cheating method is based on 1000 particularly in the higher dimensions :
1 GB = 1000 MB
1 TB = 1000 GB
...
so, when we use the mathematically correct approach, we have
8 GB = 8×1024 MB = 4×1024 = 4096 units of 2 MB.
that means that such a flash drive can store 4096 pictures.
when using the cheating approach, we have
8 GB = 8×1000 MB = 4×1000 = 4000 units of 2 MB.
the flash drive can store 4000 pictures.
6 billion pictures would then need
6,000,000,000 / 4096 = 1,464,843.75 = 1,464,844
flash drives.
or
6,000,000,000 / 4000 = 1,500,000
flash drives.
as you can see, the difference is not so small, when we are talking in big numbers.
as the manufacturers all cheat in that regard, I recommend the answer with the 1,500,000 flash drives.
