In the finite sequence of positive integers $k_1, k_2,$

Source: GMAT Prep

I the finite sequence of positive integers $k_1, k_2, k_3, . . . , k_9$ each term after the second is the sum of the two terms immediately preceding it. if $k_5=18$, what is the value of $k_9$?

1) $k_4=11$
2) $k_6=29$

The OA is D

Quote

GMAT/MBA Expert

Ian Stewart: GMAT Instructor; Posts: 2621; Joined: Mon Jun 02, 2008 3:17 am; Location: Montreal; Thanked: 1090 times; Followed by:355 members; GMAT Score:780

by Ian Stewart » Sat Jun 01, 2019 6:07 am

Timer

00:00

Your Answer

Global Stats

Since we add two consecutive terms to find the next term, once we know two consecutive terms, it is easy to work out every subsequent term in the sequence (and every earlier term, though we don't need to do that here). Using Statement 1, we know the 4th and 5th terms are 11 and 18, so the next is 29, the next is 47, the next is 76 and so on. So we can certainly find k_9 or k_93 or any other later term. The same is true using Statement 2 so the answer is D.

For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com

Quote

Post new topic Post Reply

• Page 1 of 1

5/5

5 Star (473 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review