<PRE><B>Question 830907</B>
x for how many of the 50 Rs priced
y for how many of the 70 Rs priced


x+y=60 according to the description;
50x+70y=3200 also described.  Simplify this one to 5x+7y=320.


Solve the system for x and y.
---------------
x+y=60
---------------
5x+7y=320
---------------


One way is multiply the package count equation by 5 and subtract from the revenue equation:


5x+7y-(5x+5y)=320-5*60
2y=20
y=10, meaning that x=50</PRE>