In a certain sequence, the term x(n) is given by the formula x(n) = 2xn(n-1) - (1/2)(x(n-2)) for all n >= 2. If x(0) = 3 and x(1) = 2, what is the value of x(3)?
A) 2.5
B) 3.125
C) 4
D) 5
E) 6.75
OA: C
In a certain sequence, the (OG16)
This topic has expert replies
-
- Senior | Next Rank: 100 Posts
- Posts: 93
- Joined: Mon Apr 25, 2016 2:22 pm
- Thanked: 1 times
- Followed by:1 members
- OptimusPrep
- Master | Next Rank: 500 Posts
- Posts: 410
- Joined: Fri Mar 13, 2015 3:36 am
- Location: Worldwide
- Thanked: 120 times
- Followed by:8 members
- GMAT Score:770
Hi boomgoesthegmat,boomgoesthegmat wrote:In a certain sequence, the term x(n) is given by the formula x(n) = 2xn(n-1) - (1/2)(x(n-2)) for all n >= 2. If x(0) = 3 and x(1) = 2, what is the value of x(3)?
A) 2.5
B) 3.125
C) 4
D) 5
E) 6.75
OA: C
Can you please re check the question prompt. I feel there is a problem with the term " 2xn(n-1)"
GMAT/MBA Expert
- Jeff@TargetTestPrep
- GMAT Instructor
- Posts: 1462
- Joined: Thu Apr 09, 2015 9:34 am
- Location: New York, NY
- Thanked: 39 times
- Followed by:22 members
We see thatboomgoesthegmat wrote:In a certain sequence, the term x(n) is given by the formula x(n) = 2xn(n-1) - (1/2)(x(n-2)) for all n >= 2. If x(0) = 3 and x(1) = 2, what is the value of x(3)?
A) 2.5
B) 3.125
C) 4
D) 5
E) 6.75
x(2) = 2(2) - (1/2)(3) = 4 - 1.5 = 2.5
So
x(3) = 2(2.5) - (1/2)(2) = 5 - 1 = 4
Answer: C
Jeffrey Miller
Head of GMAT Instruction
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews