Re: 11-plus grammar

Paul Wolff wrote:
the Omrud <usenet.omrud@xxxxxxxxxxxxxxxx> wrote
Arfur Million wrote:
"Leslie Danks" <leslie.danks@xxxxxx> wrote in message news:4868ab9c$0$2144$91cee783@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
If you try the test, Question 4 will tell you whether you belong to the
sheep or the rest:

<http://news.bbc.co.uk/today/hi/today/newsid_7478000/7478154.stm>
I didn't understand the scenario described (?) in question 2 at all - am I alone in this?

9 bricks in the first pile, 10 bricks in the second, etc. 7 piles, so the total number of bricks is 9 + 10 + 11 + 12 + 13 + 14 + 15.

As with many of this type of question, the total can be arrived at by the staggeringly useful formula for the area of a trapezium:

n/2(a + l)

where n is the number of steps, a is the first term and l is the final term:

7/2 (9 + 15)
3.5 x 24
84

I did it differently. There's a base rectangle seven bricks long and nine bricks high, so put 7 x 9 bricks down.

Right.

Then there are 1, 2, 3, 4, 5 and 6 bricks on top, which are easily summed as 1+6, 2+5 and 3+4, which is three lots of seven.

Aha.

n/2 (a + 1)
6/2 (1 + 6)
3 x 7

Total 12 lots of seven, or 84. It saves working with fractions until they are really needed, in some hypothetical later question.

--
David
.

Relevant Pages

  • Re: 11-plus grammar
    ... I didn't understand the scenario described in question 2 at all - am I alone in this? ... bricks in the first pile, 10 bricks in the second, etc. 7 piles, so ... where n is the number of steps, a is the first term and l is the final term: ...
    (alt.usage.english)
  • Re: 11-plus grammar
    ... alone in this? ... bricks in the first pile, 10 bricks in the second, etc. 7 piles, so ... where n is the number of steps, a is the first term and l is the final term: ...
    (alt.usage.english)
  • Re: 11-plus grammar
    ... bricks in the first pile, 10 bricks in the second, etc. 7 piles, so ... where n is the number of steps, a is the first term and l is the final ... What I did was imagine 7 piles of bricks with 9 bricks in the first pile ...
    (alt.usage.english)
  • Re: 11-plus grammar
    ... where n is the number of steps, a is the first term and l is the ... There's a base rectangle seven bricks long and ... pile and increasing by 1 brick per pile. ... Then, since subtracting 6 from 5 results in a 9 as the last digit, there was only one obvious answer. ...
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  • Re: 11-plus grammar
    ... I alone in this? ... piles of bricks are placed side by side so that their tops form steps one ... If the lowest pile contains nine bricks, ... where n is the number of steps, a is the first term and l is the final ...
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