Suppose you write a book. the printer charges $4 per book to print it, and you spend $5500 on advertising. you sell the book for $15 a copy.
a. how many copies must you sell to break even (total cost equals income from sales)?
b. what is your income (or total cost) for that many copies?

answer: internal fragmentation is the difference between the (fixed) size of a memory hole and the data within in that memory. for example, if a 1,024 byte block of memory holds 800 bytes of data, then the 224 bytes difference is considered lost to internal fragmentation.

external fragmentation occurs when the sum of memory fragments is large enough to satisfy a request, but the holes are non-contiguous and the request cannot be satisfied. this can occur when memory is dynamically allocated and freed.

explanation: