question: A tub of ice cream costing $13 is now sold at $11. A packet of milk was sold at a discount of $0.5. How much will you save if you buy 2 tubs of ice cream and 4 packets of milk?
answer: The discount for each tub of ice cream is $13 - $11 = $<<13-11=2>>2.
  So the discount for 2 tubs of ice cream is $2 x 2 = $<<2*2=4>>4.
  The total discount for 4 packets of milk is $0.5 x 4 = $<<0.5*4=2>>2.
  You will save $4 + $2 = $6 for 2 tubs of ice cream and 4 packets of milk.
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