The IBM nine-track tapes that became the industry standard for storage for three decades had several sizes , the most common being 2400 feet. The high density version stored data at 1600 bits/inch/track. If the whole tape (not including the parity track) could be used for data storage , how much raw data could one of these tapes hold?

5 MB.

Explanation:

1 foot = 12 inches

2400/9=266.66 feet per track

1 track excluding, remaining 8 track =2400 - 266.66 = 2133.33 feet

so, space available to store data = 2133.33 feet

now, 2133.33 feet = 25600 inches

total data that can be stored = 25600 * 1600 = 40960000 bits

= 46080000/8 = 5120000 Bytes

= 5120000/1000000 = 5.12 MB = 5 MB (approx.)

the answer to your question would be something called hertz. the unit of measurement called a hertz, which is one cycle per second, is used to measure clock speed. within one cycle, your computer processes, refreshes, or updates itself to the changes that it is going through. in the case of computer clock speed, one hertz equals one tick per second. the clock speed of computers is usually measured in megahertz (mhz) or gigahertz (ghz)