Author |
Message |
X96283
| Posted on Thursday, June 13, 2002 - 05:33 am: |
|
hello I am helping a friend (yes really) with the following problem. These numbers are in sequence and there's a pattern. 25,20,16,12,4/5, _____ what comes next? why? puzzled . . . giusto 00 m2 Oahu-->Bosnia |
Shot_Gun
| Posted on Thursday, June 13, 2002 - 11:34 am: |
|
Phil, if the last number is 12 and 4/5ths then the next number is 10.24, or 10 and 6/25ths. Every number is reduced by 20%. If it isn't then I'll have to go back to the drawing board. Let me know I love these math problems SG |
X96283
| Posted on Thursday, June 13, 2002 - 01:59 pm: |
|
Thanks I noticed the 20% decrease, but what got me is that there was clearly a comma between the numbers. It is not 12 4/5 but 12, 4/5 This was a sample question from one of my soldier's practice GT Test. Totally boggled my brain. Tanks and jeeps, giusto 00 M2 Oahu-->Bosnia |
Shot_Gun
| Posted on Thursday, June 13, 2002 - 02:59 pm: |
|
I give up? I been working on it an hour and haven't really come up with squat. The sequence breaks down at "16,12,4/5" You could argue that it should be "12,4/5,10,6/25" But with out more info who's to say. 4/5 doesn't seem to have any relationship with 12 so I'm lost. You will have to let us know what it is when you find the answer Give my sincere thanks to all of you for all and what you do! SG |
Blake
| Posted on Thursday, June 13, 2002 - 04:58 pm: |
|
25, 20, 16, 12, 4/5, 9, 6, 4, 2, 2/3 Looks like a once repeating five number sequence as follows... perfect square (25), perfect square - root (25-5=20), next lower perfect square (16), perfect square - root (16-4=12), inverse ratio of roots (4/5), the next lower perfect square is (9) perfect square - root (9-3=6) next lower perfect square is (4) square minus root (4-2=2) inverse ratio of roots (2/3)
|
Jst
| Posted on Thursday, June 13, 2002 - 05:38 pm: |
|
I'm not sure how 4/5 comes in but each number is 4/5ths of the number before it. IE: 20 is 4/5ths of 25 etc. If you take out the 4/5 you would have 9.6 as the next number. I'm sure there is at least one Mensa member on the board who can see a better solution than me. |
Anonymous
| Posted on Thursday, June 13, 2002 - 05:55 pm: |
|
Uh Blake...you got way too much gray matter |
Anonymous
| Posted on Thursday, June 13, 2002 - 05:57 pm: |
|
SOMETIMES I SITS AND THINKS AND SOMETIMES I JUST SITS........ |
Raymaines
| Posted on Thursday, June 13, 2002 - 06:23 pm: |
|
Blake: You're weird! |
Reindog
| Posted on Thursday, June 13, 2002 - 07:33 pm: |
|
Blake's logic is correct. It is doubtful that the comma is a typo between 12,4/5. |
Joem
| Posted on Friday, June 14, 2002 - 10:16 am: |
|
First, it has to be 12 4/5 Then, you have a Geometric Sequence where the equation is a(n) = a(1) * (r)^(n-1) Sorry, I don't have the fancy math symbols. Here we go... 25 = 25 * (4/5)^0 20 = 25 * (4/5)^1 16 = 25 * (4/5)^2 12 4/5 = 25 * (4/5)^3 10 6/25 = 25 * (4/5)^4 Or, long story short, what Shotgun said in the first place. |
|