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yrieithyddWell, I got 20/20 on the BBC English and Maths tests!
I got 63 X b-1 right, but I didn't understand why, but of the possible answers it was the one I thought it could be. I decided the -1 cancelled out one of the powers so it would equal 63-1 and this was an answer! Then there was a question which asked what 3-2 was and of the possible answers (9,1/3,6,1/9) I decided it had to be 1/9 which enabled me to understand why my first answer was right. But I really don't remember negative powers.
On the sequence, I stared at it for an age and couldn't see any link between 2, 3, 8, and 63. But wrote down factors and things and decided that each was the answer to multiplying the numbers either side of the previous (3x1 =3, 2x4 = 8, 7x9 =63) so the answer was 62x64 which was indeed one of the options. When I clicked on it it told me each was the square of the last -1. I then had to work out that n2-1 did indeed = (n-1)(n+1).
I couldn't remember how to factorise x2-2x+1 so just simplified all the answers to see which one came out right! The first of which I did very quickly having just done it with n not x!
I got 63 X b-1 right, but I didn't understand why, but of the possible answers it was the one I thought it could be. I decided the -1 cancelled out one of the powers so it would equal 63-1 and this was an answer! Then there was a question which asked what 3-2 was and of the possible answers (9,1/3,6,1/9) I decided it had to be 1/9 which enabled me to understand why my first answer was right. But I really don't remember negative powers.
On the sequence, I stared at it for an age and couldn't see any link between 2, 3, 8, and 63. But wrote down factors and things and decided that each was the answer to multiplying the numbers either side of the previous (3x1 =3, 2x4 = 8, 7x9 =63) so the answer was 62x64 which was indeed one of the options. When I clicked on it it told me each was the square of the last -1. I then had to work out that n2-1 did indeed = (n-1)(n+1).
I couldn't remember how to factorise x2-2x+1 so just simplified all the answers to see which one came out right! The first of which I did very quickly having just done it with n not x!
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Date: 2005-09-20 07:54 pm (UTC)no subject
Date: 2005-09-20 11:34 pm (UTC)no subject
Date: 2005-09-20 09:14 pm (UTC)Some of their questions could do to be better worded. The question about tennis balls and force was very sloppy. I think they really meant impulse. And one of them has x = 2 when it should be ±2. The n2-1 one took me a while.
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Date: 2005-09-21 01:23 pm (UTC)But much of the English was basic pedantry!
I'm sure that the English was harder than the maths. I think that the English questions were all based on stuff I learnt in primary school which was not the case with the maths. But having said that, the wrong answers in the maths did not seem to be plausible errors in the way that some of the English ones were. For example, the one about buying something which was reduced by 40% did not have as one of its answers the possibility of 40% of the original price whereas people do miss a c and/or an m out of accommodation!
no subject
Date: 2005-09-22 01:05 pm (UTC)I think that depends on whether or not you tried to do the maths in your head in a 'sensibly' short amount of time... (which in my case generally meant educated guesses at the answers with lots of decimal points). Sure, if you allow yourself the use paper and pencil (and as much time as you like) the maths was trivial... but even I managed the English one with the help of only one lucky guess (the meaning of Taciturn).
no subject
Date: 2005-09-23 03:47 pm (UTC)no subject
Date: 2005-09-20 11:38 pm (UTC)So for instance, 3^-2 x 3^2 = 3^0 = 1, so 3^-2 is 1/9.
no subject
Date: 2005-09-21 11:57 am (UTC)no subject
Date: 2005-09-21 01:15 pm (UTC)