A shop sells two brands of orange juice, Brand A and Brand B, as shown - Junior Cycle Mathematics - Question 6 - 2016

Now, let’s calculate the price per litre for Brand B:

• Brand B costs €1.50 for 750 ml, which is 0.75 litres.
• The price per litre is calculated as:

ext{Price per litre of Brand B} = rac{1.50}{0.75} = €2.00

Comparing both:

• Brand A: €1.80 per litre
• Brand B: €2.00 per litre

Thus, Brand A is cheaper per litre.

Samantha needs at least 5 litres of orange juice. We can calculate the cost for different combinations:

Combination 1:

• 3 x Brand A (2 litres each): $3 imes €3.60 = €10.80$
• Total = €10.80

Combination 2:

• 2 x Brand A + 2 x Brand B:
  • Cost: (2 x €3.60) + (2 x €1.50)
  • Total = €7.20 + €3.00 = €10.20

Combination 3:

• 1 x Brand A + 3 x Brand B:
  • Cost: €3.60 + (3 x €1.50)
  • Total = €3.60 + €4.50 = €8.10

Combination 4:

• 5 x Brand B:
  • Cost: 5 x €1.50 = €7.50

Comparison of totals:

• €10.80 (Combination 1)
• €10.20 (Combination 2)
• €8.10 (Combination 3)
• €7.50 (Combination 4)

The lowest price is €7.50 for 5 litres of Brand B.