Question 1190794
<pre>
Whenever you have a numbered set of things, the number of elements is the ending number minus the starting number, plus 1:

Examples:

If we number the elements of {ABCDE} starting from 0, we get:

   A    B     C     D     E  
   0    1     2     3     4     --> number of elements = 4-0+1 = 5

and if we start at 1:
   A    B     C     D     E
   1    2     3     4     5     -->  number of elements = 5-1+1 = 5
(you see here when you start counting with "1" the -1 and +1 always cancel and you can just pick the ending number for this common case)



i)  100 maps to 25  (100/4 = 25)
    104 maps to 26
     ...
    300 maps to 75         ---> number of elements of interest = 75-25+1 = {{{ highlight(51)}}} 


ii)  Here, we are looking for the inverse.   300-100+1 = 201 total elements, and if we take out the 51 found in part (i), we are left with  {{{highlight( 150)}}} elements of interest.