Haps Boys maths 2016

[Guest55]

£3 each
C Buy two get one free
D Buy four and pay only for three
E One-third of all price

C) pay £6 and get 3 so £2 each

D) pay £9 and get 4 so £2.25 each

E) pay £2 and get one so £2 each [one third of £3 is £1 so cost is two thirds]

Most people [but not ToadMum] find it easier to use a specific value ...

[ToadMum]

With £12 in hand and price per item is £3 pound I get following answers

A offer will give me 8 items [ Buy one get one free] so per pound I get 2/3 of item

B offer will give me 5 items [ Buy one get the second for half price ] so per pound I get 5/12 item

C offer will give 6 items [ Buy two get one free] so per pound 1/2 item

D offer will give 5 items [ Buy four and pay only for three] so per pound 5/12 item

E offer will give 12 items [ one-third of all prices] so per pound 1 item

so my answer is only B and D will give same value for money , however I didn't get another pair of same value.

Any help ?

I don't think I would do it like that (sorry, Guest55 )

A Buy one get one free
Get two, pay for one
Get four, pay for two


B Buy one get the second for half price
Get two, pay for one and a half
Get four, pay for three

C Buy two get one free
Get three, pay for two (alternative way of saying this: pay for two-thirds of what you get?)

 D Buy four and pay only for three

E One-third of all prices 
Get three, pay for...?

Now can you see another pair?

E will be get three and pay for one. which is equal to 1/3 isn't ? sorry I'm trying to understand this but failing. Can you give me more clue ? could not do it

I assumed that the 'One third of all prices' was meant to be 'one third off all prices? Which would make it 'get three, pay for two'.

[Surferfish]

I assumed that the 'One third of all prices' was meant to be 'one third off all prices? Which would make it 'get three, pay for two'.

I agree that E is probably a typo and should read 'off' rather than 'of'. (very badly worded question in this respect).

Anyway assuming E should be 'off', I'd tackle it in a slightly different way.

A Buy one get one free = 2 for price of 1
B Buy one get the second for half price = 2 for price of 1.5
C Buy two get one free = 3 for price of 2
D Buy four and pay only for three = 4 for price of 3
E One-third OFF all prices = 1 for price of 2/3

I can now spot which 2 pairs are the same offers but you can work them out using a common multiple (6) just to make it clear.

A Buy one get one free = 2 for price of 1 = 12 for 6
B Buy one get the second for half price = 2 for price of 1.5 = 8 for 6
C Buy two get one free = 3 for price of 2 = 9 for 6
D Buy four and pay only for three = 4 for price of 3 = 8 for 6
E One-third OFF all prices = 1 for price of 2/3 = 9 for 6

[streathammum]

I just had a go at this. I imagined that each item costs 10p. So you end up with something like this:

You pay Value of what you get Amount you pay as a fraction of its value
A 10p 20p 1/2 (half)
B 15p 20p 3/4 (three-quarters)
C 20p 30p 2/3 (two-thirds)
D 30p 40p 3/4 (three-quarters)
E 20p 30p 2/3 (two-thirds)

I found that easier than trying to start with a fixed amount and seeing what it would buy you.

ETA - cross-posted with others, sorry

[Guest55]

Yes, that's basically the same way I tackled it.

It's great that peeople see it in different ways but children tend to prefer a 'concrete' method ie allocate a cost to something.

[streathammum]

I think my overall approach to maths is very similar to that of children at primary school

[Guest55]

I think my overall approach to maths is very similar to that of children at primary school

That is often the better approach for 11+ questions - too many people leap into inappropriate algebra [not in this question but many others people have posted].

[streathammum]

There's no danger of me doing that.

[solimum]

I found it easier to draw squares representing the object, and assume a price of £10 each (tried to upload a picture but can't work out how to do that, so will use some smileys instead)

A) £10
B) £15
C) £20
D) £30
E) £6.67
£13.33
£20

It's then easy to see that C and E are equivalent, and then of the remaining three D and B also match up

(obviously in my mind the product was something like a bottle of wine!)