<PRE><B>Question 814648</B>
Set c = number of burgers with cheese
Set w = number of burgers without cheese

c = 1/2 * w   One half as many have cheese

w + c = 495   The number without plus the number with equal 495

Notice that we can substitute ( 1/2 * w ) for c in the above equation
w + ( 1/2 * w ) = 495
1 1/2 * w = 495
or 
3/2 w = 495
Multiply each side by 2/3
(2/3)(3/2) * w = 495 * (2/3)
           w = 990/3
           w = 330
Since w + c = 495
      390 + c = 495
          c = 165
So we have 165 with cheese and 390 without.</PRE>