In order to find out the necessary information to solve the problem you must ask all the right (and correct!) questions. Here are some tips to help you avoid mistakes.

• Make sure you use the correct word order: (Wh- word) + Aux + S + V.

• Use the present simple for all your questions, to make it —well, simpler.

• Do not start your questions with "which", use "what".

• Do not use "1" when you can say "a".

• Remember to use British spelling: "litre" is British spelling, "liter" is American spelling.

• Take notes in your notebook of the information you find out.

• One final clue: all the questions you need to ask can have 8 words only (but you can also get useful information with slightly different questions).

How many data did you learn from your questions? Write a number only, please, and do not use a full stop; example:

3

What do you need to calculate first?

Let's imagine that the price of a box of wine is £20.
To calculate the price of the wine you can use a "rule of three".



But you can also use a "conversion factor":



As you can see, the fraction in the conversion factor has equivalent amounts (in different units) in the numerator and the denominator. This means that we are really multiplying by one, but we obtain a different unit as the result.

To achieve this, we must put the unit that we want to transform into another in the denominator, and the unit that we want to obtain in the numerator.

The advantage of this system over the rule of three is that you can do several calculations in a single operation (we will see how in question number 6).

Use the conversion factor that you wrote down in your notebook to calculate the real price of the wine that the pub owner bought, then answer the question below.

If your answer is not correct, repeat your calculations, making sure you have the correct data; you can check your data in question 1.

IMPORTANT: write a number only, not the unit. Do not use a full stop. Example: 55

How many pounds did the pub owner pay for the wine?

Now what must you calculate?

We have to use several "conversion factors" to transform one unit (the number of boxes that the pub owner bought) into another unit (the amount of wine in some standard unit, like litres).

Study how this is done using conversion factors:



Now fill in the gaps with your data and calculate the result in your notebook.
IMPORTANT: write a number only, not the unit. Do not use a full stop. Example: 55

How many litres of wine did the pub owner buy?

Now what do you have to calculate?

Again we can use several "conversion factors" to transform the number of jugs of water that the pub owner added to the wine into the same standard unit (litres) that we used for the wine, so that we can add together the wine and water and calculate the amount of mixture. Study how this is done, fill in the gaps with your data and calculate the result:



Now fill in the gaps with your data and calculate the result in your notebook.

Then, add together the wine and water.

How many litres were there in the barrel? (write a number only).

Now what do you have to calculate?

Now we must calculate the gross income, so we use several conversion factors again to transform the amount of wine mixed with water (in litres) into money (in pounds). Study how this is done, fill in the gaps with your data and calculate the result in your notebook:



How many pounds did the pub owner get for the wine mixed with water? (write a number only).

OK, let's sum up. We have found out the following data:

Question 4: The price of the wine that the pub owner bought.
Question 6: The amount of wine that the pub owner bought.
Question 8: The amount of water he added to the wine.
Question 10: The amount of money that he got when he sold the wine mixed with water.

What do we need to do now?

To find out the benefit you must subtract the money he paid for the wine from the money he got when he sold it.

So, how many pounds did the pub owner earn in the end? (Write a number only).