📖Definition
In these questions you'll be given some facts/statements and then asked a question on them.
✏️Example
Ben, Chris, Daisy, Emily, and Frank play five different musical instruments between them.
Only Ben, Daisy and Frank play the drums.
Everyone but Chris plays the violin.
Daisy and Chris are the only ones who don't play the piano.
The recorder and flute are only played by Chris and Emily.
If the above statements are true, which of the following CANNOT be true?
A Frank doesn't like practising.
B The same number play the piano as the drums.
C Emily plays the most instruments.
D Daisy plays more instruments than Ben.
E Chris plays two instruments.
Knowledge Required
These are all about logic. The only way to improve is to practise. There are a few different types but the information is ALL THERE in the question. You just need to get it out!
✅How To Answer
Method 1
Although they might not look it at first sight, these are basically straightforward if you take them step by step.
This type usually involves 5 different people and information about something they do/like/own etc.
With this type, it often helps to draw a table like so. Although some questions can be answered by directly using the information you're given (eg. Answer B) it doesn't harm to have as much information in the table as possible.
Diagram
Now add the information into it statement by statement.
Only Ben, Daisy and Frank play the drums.
We can put a tick by them and a cross by the others.
Diagram
Everyone but Chris plays the violin.
So, add a tick to everyone but Chris who gets a cross.
Diagram
Daisy and Chris are the only ones who don't play the piano.
Add a cross to each of them in the piano column and a tick for the others.
Diagram
The recorder and flute are only played by Chris and Emily.
And finally, add two ticks to each of them.
Diagram
So you've created a table containing all the information.
Now use it to check each of the answers. Don't forget, we're looking for an answer that CANNOT be true ie. must be false.
A Frank doesn't like practising.
Well, how can we tell? We can't. This is a red herring. They often crop so don't be surprised by them, just move on to the next answer.
B The same number play the piano as the drums.
Looking at the table, that's true.
C Emily plays the most instruments.
Looking at the table, that's true too.
D Daisy plays more instruments than Ben.
Looking at the table, that's false. Daisy plays 2 instruments and Ben plays 3. So D is the answer.
E Chris plays two instruments.
As a final check, looking at our table, yes he does so that confirms that D is the right answer.
Variances
A variation on this type of question will involve a straight question at the end, in the above example it could be 'Who plays the most instruments?' Again, draw a table to find the answer.
Also, in this question, each statement was explicit in who did and didn't play certain instruments so we could fill in both ticks and crosses. Sometimes, this won't be the case and some of the table spaces will be left blank. Normally in questions like that, you'll be asked to identify which of five statements must be true or must be false.
✏️Example
Five friends, Lisa, Maisie, Nigel, Ollie, Pooran celebrate their birthdays in the first five days of May.
Each has their birthday on a different day.
Nigel's birthday is the day before Maisie's.
Ollie's birthday is the day after Pooran's.
Lisa's birthday is May 3rd.
Maisie's birthday is either May 2nd or May 4th.
What is the date of Ollie's birthday?
Method 2
This is another type which involves putting things (usually 5 of them) in order.
Again, it looks harder than it actually is. Draw a table.
Diagram
Look through the statements and find the most straightforward facts to fill in the table.
Lisa's birthday is May 3rd.
That's simple enough.
Diagram
Do you see what was done there? We put a tick by May 3rd and we eliminated all the other possible dates for Lisa's birthday. Not only that, as everyone has their birthday on a different day, nobody else's birthday can be May 3rd so we eliminate that date from the possible dates for everyone else's birthday.
The next one to consider is:
Maisie's birthday is either May 2nd or May 4th.
Whilst we don't know for definite which it is, we can eliminate dates which aren't her birthday.
Diagram
Now let's look at the first statement:
Nigel's birthday is the day before Maisie's.
We know Maisie's is the 2nd or 4th so Nigel's must be the 1st or 3rd.
Put this into the table.
Diagram
Do you see what happened? From the table, we could see that it wasn't the 3rd as Lisa's is then so it has to be May 1st.
Now look at the remaining statement.
Ollie's birthday is the day after Pooran's..
From the table, Pooran's birthday has to be the 2nd, 4th or 5th.
That means, Ollie's must be the 3rd, 5th or 6th.
It's not the 3rd because that's Lisa's and it's not the 6th because it's between the 1st and 5th so it must be the 5th.
And that's our answer. There's no need to complete the table, it's work is done.
And some questions are just downright baffling!
✏️Example
If the day after the day after tomorrow is Wednesday, what was the day before the day before yesterday?
It will help here to draw a list of the days of the week.
Diagram
Let's break the question down into two parts.
Firstly, we're told the day after the day after tomorrow is Wednesday.
Diagram
Tuesday must be the day after tomorrow, Monday must be tomorrow and so Sunday must be today. We're going to need some more days adding!
We want to find the day before the day before yesterday. Work backwards from today.
Diagram
So the answer is Thursday.
Phew!
And here's another!
✏️Example
Read these three statements:
All unicorns are blue.
Sparkle is blue.
Krystal is a unicorn.
Find the statement below which MUST be true.
A Sparkle is a unicorn.
B Dragons are never blue.
C Krystal is blue.
D Sparkle isn't a unicorn.
E Sparkle is a dragon.
Let's look at the information we've been given.
All unicorns are blue so any creature that's a unicorn is blue.
Sparkle is blue - that doesn't really tell us anything as, although all unicorns are blue, not all blue things are unicorns.
Krystal is a unicorn so, following on from the first statement, Krystal must be blue.
Looking at the answers, C must be true.
💡Tips/hints
And finally...always be careful that you don't read more into the information given than is there. If you draw a table, be aware that it may not be complete. It is merely a record of the facts you KNOW to be true.