Answer:
40%
Step-by-step explanation:
Every week you he buys 4 number of 2 Litres bottle of lemonade.
Thus, let's say cost of each bottle is X.
This means he total cost is 4X
Now, total litres = 4 × 2 = 8 litres
Thus, cost per litre = 4X/8 = ½X
Now, we are told that Last week the bottles on the shelf were limited edition “2.5 litres for the price of 2 litres” bottles ".
This means that now, it is cheaper.
However, the supermarket also had a “buy 3 bottles, get another one free” offer.
Now since he buys 8 litres weekly, now since it's 2.5 L bottle, he will buy 3 since he will be given 1 free for every 3 he buys.
Thus, total litres he is paying for = 2.5 × 3 = 7.5 litres
Thus, cost per bottle is; 3X
Since he is getting 1 bottle free, then total bottle he gets is; 7.5 L + 2.5 L = 10L
Thus;
cost per litre is now; 3X/10
Difference in costs per litre is;
½X - 3X/10 = X/5
percentage of the cost of four bottles of lemonade lower than usual last week = (X/5)/(½X) × 100% = 2/5 × 100% = 40%
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