Can YOU solve this sequence?

(35 Posts)
caraway Mon 01-Oct-12 19:15:41

There's a chocolate prize up for grab- a tin of Celebrations- and I'm desperate for help. It goes- 100, 200, 400, 800, 1500. If only there wasn't the 1500. I've tried everything- adding then dividing, multiplying, seeing if it jumps. Anyone know the answer, or could give ideas on how to do it? The 'homework' is a parent's competition- the form actually said 'you can use outside help'. If you know the answer, can you give advice on how you got it instead of telling me the answer (I want to know how it's done, not just know the answer).

alanyoung Sat 02-Feb-13 19:34:26

Did you ever find the answer?

arkestra Tue 08-Jan-13 15:48:54

(and now I realise I've woken a zombie thread, never mind)

arkestra Tue 08-Jan-13 15:45:33

(Kind of a blunderbuss approach - but if it's in a sequence you will find it here!)

arkestra Tue 08-Jan-13 15:44:39

http://oeis.org/search?q=100%2C+200%2C+400%2C+800%2C+1500&language=english&go=Search

richmal Tue 02-Oct-12 16:50:11

Oops, You did not want the answer. I will ask for it to be deleted.

Basically, look for the gaps in the gaps in the gaps.

richmal Tue 02-Oct-12 16:36:04

Message withdrawn at poster's request.

They really should have given just one more number! grin

caraway Mon 01-Oct-12 20:16:36

So is it Shelium or WillieWaggledagger? If it's WillieWaggledagger, I think it would be 2600 and 4200. Or Shelium. Or the running track. I think it's meant to be math-sy, but I'm not sure. Do you think I could ask if it's meant to be maths-based or anything?

Shelium Mon 01-Oct-12 19:54:17

100
200
400 = 200 (previous number) + 100 (number before that) +100
800 = 400 (previous number) + 200 (number before that) +200
1500 = 800 (previous number) + 400 (number before that) +300

? = 1500 (previous number) + 800 (number before that) +400 = 2700
?? =2700 (previous number) + 1500 (number before that) +500 = 4700

TwinMummy30 Mon 01-Oct-12 19:48:39

oops wrong! just saw it 400+900 isnt 1500 blush

TwinMummy30 Mon 01-Oct-12 19:45:39

hi i think i have it but not sure so...
100, 200, 400, 800, 1500, 2000, 3000
100+300=400
200+600=800
400+900=1500
800+1200=2000
1500+1500=3000

they are going up by 300, ..... if you jump every other

anyone correct me if I did it wrong blush

notcitrus Mon 01-Oct-12 19:36:28

I bet its the Olympic running distances - topical innit.

BikeRunSki Mon 01-Oct-12 19:35:29

I'm going with running too.

Message withdrawn at poster's request.

Melpomene Mon 01-Oct-12 19:32:25

I think it's running distances and the next two would be 5000 and 10,000 (distances included in the Olympics).

DowntonTrout Mon 01-Oct-12 19:32:25

But as there are clearly two different, but clearly correct answers you could point that out and maybe that will swing you the prize!

slambang Mon 01-Oct-12 19:32:16

Oh no, it isn't. blush. Yeah running.

Message withdrawn at poster's request.

Running distances in metres? I would say the next two in the sequence would be 5,000 and 10,000 (unless you count the steeplechase at 3,000 metres)

slambang Mon 01-Oct-12 19:31:18

Nah - it's adding odd numbered 100s in sequence
add 100, add 300, add 500, add 700 ...

bigkidsdidit Mon 01-Oct-12 19:29:54

I too think it's running distances and would go with 5000 and 10000

ginmakesitallok Mon 01-Oct-12 19:29:45

I'd have thought running distances too - so would be 5,000 then 10,000?

meditrina Mon 01-Oct-12 19:29:20

I've just looked and it's not Millionaire prize money.

The running distances work, but then you get two possible answers: 3000 5000 (indoors only) or 5000 10000 (outdoors).

DowntonTrout Mon 01-Oct-12 19:29:07

Oops too late and clearly wrong!

DowntonTrout Mon 01-Oct-12 19:28:23

I would guess the next 2 are 5,000 and 10,000.

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