Can anyone solve it - and how did you come up with the solution? This is beginning to drive me crazy! What is the best way to go about solving these?
2006-12-18 08:11:07 · 10 answers · asked by Frannie_kins 1 in Science & Mathematics ➔ Mathematics
Wow - thanks :) we are very impressed with your immense knowledge!
2006-12-18 08:25:13 · update #1
this is a recursive function (ill call it u)
u0 = 2
u1 = 2 + 9*u0
u2 = 2 + 9*u1
... ...
un = 2 + 9*u(n-1)
so the next number would be 2 + 9(2 + 9(2 + 9(2 + 9*2))) = 14762
as for the best way to go about these, look how fast it's increasing/decreasing and work from there
2006-12-18 08:17:38 · answer #1 · answered by Anonymous · 3⤊ 0⤋
14762
Taking the numbers in pairs, multiply the difference by 10 and add the lower number ...
which is the same as 10 times the higher number minus 9 times the lower number.
(20-2)*10+2=182
(182-20)*10+20=1640
(1640-182)*10+182=14762
or
(20*10)-(2*9)=200-18=182
(182*10)-(20*9)=1820-180=1640
(1640*10)-(182*9)=16400-1638=14762
How ? Can't always see them, but the first way seemed to leap out at me this time.
2006-12-18 23:04:39 · answer #2 · answered by Cassandra 3 · 0⤊ 0⤋
Look for a pattern. If you subtract 2 from every number
after the 2nd, what do you see? Each number
is 9 times the previous one.
So in your case, each term is 9 times the previous one
plus 2. So the next number is 1640*9 + 2 = 14762.
2006-12-18 16:17:54 · answer #3 · answered by steiner1745 7 · 3⤊ 0⤋
1st 2 = A1
2nd 20 = A2
3rd 182 =A3
4th 1640 =A4
what is A5=
I knew it was not linear. I knew it was not logarithmic. I saw that 18 was 2 less than 20 how do I turn 20 into 180?
A3= ((A2-A1)*10)+A1
182 = ((20-2)*10)+2
A4= ((A3-A2)*10)*A2
1640= ((182-20)*10)+20
A5= ((A4-A3)*10)+A3
14762=((1640-182)*10)+182
A6 =132860
trial and error and guess work.. Once you start getting close, then change the formual slightly to try to make it work. I did it different than Tom.... I guess it shows you that there is more than one way to skin a cat.
2006-12-18 17:23:43 · answer #4 · answered by Mr Cellophane 6 · 0⤊ 1⤋
9 * 1640 +2 = 14762
2006-12-18 16:15:10 · answer #5 · answered by gianlino 7 · 3⤊ 0⤋
If the nth number is x, the (n + 1)th number is 9x + 2
9(1640) + 2 = 14762
2006-12-18 16:17:13 · answer #6 · answered by Tom :: Athier than Thou 6 · 3⤊ 0⤋
How about this?
Take 9 times each number and add 2 to get the next number.
I don't know of any way other than to stare a tthe sequence and see if anything jumps out at you.
2006-12-18 16:17:54 · answer #7 · answered by firefly 6 · 3⤊ 0⤋
urg i hate math sorry i reli cant help you hun try a calculator though there what i use but hope some one can help you cause i acsually reli wanna know how thinking of it loll :):):)
2006-12-18 16:14:57 · answer #8 · answered by francho 3 · 0⤊ 4⤋
24675
2006-12-18 16:29:21 · answer #9 · answered by Cu Den 2 · 0⤊ 2⤋
16401
2006-12-18 16:20:49 · answer #10 · answered by David H 6 · 0⤊ 3⤋