Tricky maths question
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Tricky maths question
This is a question from an independent school maths practise paper, my daughter cannot solve it and neither can I.
You are given a grid with 9 squares (3 across, 3 down etc). You have to insert the figures 2, 2, 2, 3, 3, 3, 4, 4, 4 - so that each line, including diagonally, adds up to nine. I can't do it. Is it a trick question or am I missing something?
Thank you.
You are given a grid with 9 squares (3 across, 3 down etc). You have to insert the figures 2, 2, 2, 3, 3, 3, 4, 4, 4 - so that each line, including diagonally, adds up to nine. I can't do it. Is it a trick question or am I missing something?
Thank you.
The trick is to recognise that there are only 2 combinations of 3 numbers from the set that add up to 9, Either 2,3,4 or 3,3,3.
You need to recognise that having a different combination of 2,3 &4 in the rows (and columns ) will give the desired results for the rows and columns, but the only way the diagonals will add up to 9 is if one of these is 3, 3 & 3.
So start out by populating one of the diagonals with 3s and then just make sure the each of the rows has a different permutation. viz.
3xx
x3x
xx3
342
234
423
Ken
You need to recognise that having a different combination of 2,3 &4 in the rows (and columns ) will give the desired results for the rows and columns, but the only way the diagonals will add up to 9 is if one of these is 3, 3 & 3.
So start out by populating one of the diagonals with 3s and then just make sure the each of the rows has a different permutation. viz.
3xx
x3x
xx3
342
234
423
Ken
I've had lots of practice having gone through every paper I could find last year with my son. So I am fairly confident that I could now pass my 11+ second time round!
I found the Independent school exams are quite different to the normal 11+ grammar exams, the maths questions in particular seem to be graduated and get quite hard towards the end. I guess this is to test the scholarship level candidates.
I recall a practice paper we were sent from Solihull School last year which had a tough question about a boat and a hovercraft going in different directions and speeds around a lake. The candidates had to work out when the boat/hovercraft would pass and how far they had travelled.
The best way to work it out was by using algebra but strictly speaking they shouldn't have done this at KS2.
I found the Independent school exams are quite different to the normal 11+ grammar exams, the maths questions in particular seem to be graduated and get quite hard towards the end. I guess this is to test the scholarship level candidates.
I recall a practice paper we were sent from Solihull School last year which had a tough question about a boat and a hovercraft going in different directions and speeds around a lake. The candidates had to work out when the boat/hovercraft would pass and how far they had travelled.
The best way to work it out was by using algebra but strictly speaking they shouldn't have done this at KS2.
I gave this to both my little darlings (boys) and my big darling and all managed easily in under a minute. Maybe its just mum who's thick - despite a grammar school education!!I've had lots of practice having gone through every paper I could find last year with my son. So I am fairly confident that I could now pass my 11+ second time round!