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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE General & Further Mathematics => Topic started by: Defiler on November 05, 2007, 01:32:27 pm

Title: Exam One Number Patterns
Post by: Defiler on November 05, 2007, 01:32:27 pm

Mine

1. B
2. C
3. B
4. C
5. E
6. B
7. E
8. D
9. A

Title: Re: Exam One Number Patterns
Post by: Odette on November 05, 2007, 01:34:14 pm

Quote from: "Defiler"

Mine

1. B
2. C
3. B
4. C
5. E
6. B
7. E
8. D
9. A

Same, except for 7, how did you get E?

Title: Exam One Number Patterns
Post by: Defiler on November 05, 2007, 01:36:21 pm

t1 = positive, so it can't be D

If the ratio if negative ... let's say it starts at t1=4

4 x -.5 = -2
-2 x -.5 = 1

and hence it goes pos-neg-pos-neg-pos

and that's how I got E

Title: Exam One Number Patterns
Post by: Odette on November 05, 2007, 01:37:45 pm

Quote from: "Defiler"

t1 = positive, so it can't be D

If the ratio if negative ... let's say it starts at t1=4

4 x -.5 = -2
-2 x -.5 = 1

and hence it goes pos-neg-pos-neg-pos

and that's how I got E

Oh ok :)

Title: Exam One Number Patterns
Post by: dxb on November 05, 2007, 01:47:32 pm

what about 9? I got C - 150....

Edit, other than that, I got all the same too.

Title: Exam One Number Patterns
Post by: Defiler on November 05, 2007, 01:48:35 pm

Quote from: "dxb"

what about 9? I got C - 150....

Well I did it long-hand (e.g. adding up the all the numbers and obtained A... odette got A as well so I assume it is correct)

15+12.5+12.15+10.94+9.84+8.86+7.97+7.17+6.46+5.81+5.23+4.71+4.24+3.81=115.685

Title: Exam One Number Patterns
Post by: Odette on November 05, 2007, 01:51:07 pm

Question 9 is A...
Here's how i worked it out:
t14= 15(1-0.9^14)/1-0.9
     = 115.68
     which is approximately 116

Title: Exam One Number Patterns
Post by: dxb on November 05, 2007, 01:59:41 pm

AHhhh shit, i see what i did, i thought it was a infinant and not 14.