Question 204960
Mary buys 100 candies for $7.00 . 
if yips cost 5 cents each. gups 6 cents each and pips 7 cents each,
 How many more pips than yips did mary buy?
:
y + g + p = 100; (total candies)
:
.05y + .06g + .07p = $7.00; (total cost)
:
Multiply the 1st equation by .06 and subtract from the above equation
.05y + .06g + .07p = 7
.06y + .06g + .06p = 6
--------------------------subtraction eliminates g
-.01y + .01p = 1
Multiply above equation by 100 to get rid of the decimals
-1y + 1p = 100
we can write it
p - y = 100, answers the question" How many more pips than yips did mary buy?"