Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 06 May 2015, 14:54

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A man saves $4 more each year than the preceding year. If  Question banks Downloads My Bookmarks Reviews Important topics Author Message TAGS: Director Joined: 24 Oct 2005 Posts: 660 Location: London Followers: 1 Kudos [?]: 7 [0], given: 0 A man saves$ 4 more each year than the preceding year. If [#permalink]  28 Nov 2005, 02:10
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
A man saves $4 more each year than the preceding year. If he saves Rs 20 in the first year, after how many years will his savings amount to$1064?
a) 10
b) 12
c) 18
d) 19
Director
Joined: 14 Sep 2005
Posts: 994
Location: South Korea
Followers: 2

Kudos [?]: 44 [0], given: 0

A man saves $4 more each year than the preceding year. If he saves Rs 20 in the first year, after how many years will his savings amount to$1064?

A(n) = A(n-1) + 4

A(1) = 20
A(2) = 20 + 4
A(3) = 20 + 4 + 4
A(4) = 20 + 4 + 4 + 4
.
.
.
A(N) = 20 + 4(N - 1)

A(1) + A(2) + A(3) + A(4) + ... + A(N)
= (20 * N) + 4(0 + 1 + 2 + 3 + ... + N-1)
= (20 * N) + 4( (N-1)N/2 )
= (20 * N) + 2(N^2) - 2N
= 2(N^2) + 18N
= 1064

N^2 + 9N = 532
N^2 + 9N - 532 = 0
(N-19)(N+28)=0

N=19 or N=-28

A year must be positive.

Thus, he needs to save for 19 years.

(E) it is.
_________________

Auge um Auge, Zahn um Zahn !

Similar topics Replies Last post
Similar
Topics:
10 Setting a precedent that lasted more than a century,George 9 06 Oct 2013, 07:07
7 Each year companies in the United State could save as much 12 18 Jul 2012, 15:58
12 Each year companies in United States could save as much as 11 26 Jun 2012, 05:21
1 A person saves each year Rs 100 more than he saved in the 5 04 Apr 2012, 19:16