sequence

**nurf** · 04-05-2010, 03:12 PM

A1 = 0

An = 1/2 An-1 + 4

A100 = ???

please explain

**rina777** · 04-05-2010, 06:23 PM

there is something wrong with this question???????????

**nurf** · 04-05-2010, 06:24 PM

no.

its a 100% real original gre question

**rose0550** · 04-05-2010, 07:34 PM

A1 =0
A2= 1/2 *A1* 4 ==> 1/2 * 0 * 4(place A1=0)
A3=1/2* A2 *4==> 1/2 *0 * 4
....................
Every term in the sequence is 0 so A100=0.
wjhat is the answer?

**nurf** · 04-05-2010, 08:25 PM

oh **** sorry guys, it has to be

An = 1/2 * An-1 + 4

sorry

**rina777** · 04-06-2010, 02:04 AM

An would be approximatey 8.

**abaabeel** · 04-06-2010, 07:37 AM

It should be 8 since after A4 the values keep increasing in fraction towrds 8. What is the answer nurf?

**nurf** · 04-06-2010, 07:44 PM

i dont know what the answer is, it came up on my gre last week.

but 8 was one of the possible answers and i choose it too.

guess this wasnt the question responsible for my failure