3) At a fast food stall only three items are sold: Sandwich, Burger & Soya Milk Bottle. A Sandwich , a Burger & a Soya Milk Bottle together cost Rs.6. For Rs.9 and 50 paise you can buy 2 Sandwiches, 1 Burger & 1 soya Milk Bottle. A Sandwich and a Soya Milk Bottle can be purchased for Rs.4 and 70 paise. Mickey purchases 3 Sandwiches, 2 Burgers & 1 Soya Milk Bottle for his breakfast. Mickey pays by a Rs.50 note, what change must he receive?

Solution:

Sandwich:x

Burger:y

Soya Milk Bottle: z

So

x+y+z=6

2x+y+z=9.50

x+z=4.70

So

x=3.50

y=1.30

z=1.20

So

3x+2y+z=3*3.50+2*1.30+1.20=14.30

Change=50-14.30 = 36.70