7. Fionn is buying a new mobile phone. He can choose one of the following monthly packages. Assume a month has 30 days.
Pay as you go No monthly charge
For the fi rst 2 minutes of calls each day: 10 cents per minute
For the rest of that day: 5 cents per minute 5 gigabytes of data per day
€15 monthly charge For the fi rst 3 minutes of calls each day: no charge
For the rest of that day: 3 cents per minute Unlimited data
Fionn reckons he spends 10 minutes on the phone each day. He uses 3 gigabytes of data each day. (i) Which tariff should he choose? Justify your answer by showing all your work.
(ii) Fionn’s mother also buys a phone. She knows she will defi nitely spend 80 minutes on the phone each day, but will not use any data. Which package should she choose? Justify your answer by showing all your work.
(iii) When is RED 15 the cheaper package? Justify your answer by showing all your work. 13·4 Profi t and loss
By the end of this section you should be able to: ● calculate profi t and loss using percentages
When you purchase an item and sell it for more money than you have paid, you have made a profi t. However, if you purchase an item and sell it for less than you originally paid, you have made a loss. You have already met many of the terms associated with this topic in Section A, Unit 5.
Profi t: if the selling price is greater than cost price
Profi t or gain = selling price – cost price (Note: profi t will be a positive value)
If an article is sold at a profi t of 10%, then the selling price = 110% of cost price. Percentage profi t = profi t
________ cost price × 100
___ 1
Loss: if the selling price is less than cost price
Loss = selling price – cost price (Note: loss will be a negative value)
If an article is sold at a loss of 10%, then selling price = 90% of cost price. Percentage loss = loss
_______ cost price × 100
___ 1
In general, we express profi t or loss as a percentage of the cost price, unless instructed to do otherwise.
Worked example 1 Andy buys a car for €4 000. He then sells it for €5 500. Find the value of the following in euros: (i) The cost price (ii) the selling price (iii) the profi t or loss made (iv) the percentage profi t or loss.