the infinite sequence a1, a2....an is such that a1 = 7,a2 =8, a3 =10 and an =a_(n-3)+7 for values of n>3. what is the remainder when an is divided by 7?
a)n is the multiple of 3..
b)n is an even no..
oa after some discussion
source : veritas prep test
experts plz help
This topic has expert replies
-
- Legendary Member
- Posts: 966
- Joined: Sat Jan 02, 2010 8:06 am
- Thanked: 230 times
- Followed by:21 members
Statement 1
Given a3 = 10 - Remainder 3
a6 = a3+7 = 17 - Remainder 3
a9 = a6 + 7 = 24 - Remainder 3 (You add a multiple of 7, remainder does not change)
Sufficient.
Statement 2
Given a2 = 8 - Remainder 1
Now we have already calculated a6 (even no) previously and got a different remainder (3)
SO different results - Insuff
A IMO
Given a3 = 10 - Remainder 3
a6 = a3+7 = 17 - Remainder 3
a9 = a6 + 7 = 24 - Remainder 3 (You add a multiple of 7, remainder does not change)
Sufficient.
Statement 2
Given a2 = 8 - Remainder 1
Now we have already calculated a6 (even no) previously and got a different remainder (3)
SO different results - Insuff
A IMO
- amit2k9
- Master | Next Rank: 500 Posts
- Posts: 461
- Joined: Tue May 10, 2011 9:09 am
- Location: pune
- Thanked: 36 times
- Followed by:3 members
a1,a2,a3 = 7,8,10
a4,a5,a6= 14,15,17
a. a3 and a6 have 10 and 15. meaning remainder = 3. sufficient.
b a2,a4 have remainders 1 and 0. hence not sufficient.
A it is.
a4,a5,a6= 14,15,17
a. a3 and a6 have 10 and 15. meaning remainder = 3. sufficient.
b a2,a4 have remainders 1 and 0. hence not sufficient.
A it is.
For Understanding Sustainability,Green Businesses and Social Entrepreneurship visit -https://aamthoughts.blocked/
(Featured Best Green Site Worldwide-https://bloggers.com/green/popular/page2)
(Featured Best Green Site Worldwide-https://bloggers.com/green/popular/page2)