In a certain sequence , the tern Xn is given by formula Xn= 2Xn-1/2 ( Xn-2) for all n greater than or equal to 2.If X0= 3 and X1= 2 what is the value of X3.
a. 2.5
b. 3.125
c. 4
d. 5
e. 6.75
Ans c
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
sequence
This topic has expert replies
GMAT/MBA Expert
-
Rahul@gurome
- GMAT Instructor
- Posts: 1179
- Joined: Sun Apr 11, 2010 9:07 pm
- Location: Milpitas, CA
- Thanked: 447 times
- Followed by:88 members
I think the question is wrongly posted .
Xn should be Xn = 2X(n-1) - ½*X(n-2).
So X2 = 2X1 - ½ *X0 = 2*2 - ½ * 3 = 4 - 3/2 = 5/2.
Or X3 = 2*5/2 - ½ * 2 = 5 - 1 = 4.
The correct answer is hence C.
Xn should be Xn = 2X(n-1) - ½*X(n-2).
So X2 = 2X1 - ½ *X0 = 2*2 - ½ * 3 = 4 - 3/2 = 5/2.
Or X3 = 2*5/2 - ½ * 2 = 5 - 1 = 4.
The correct answer is hence C.
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
