divisor?

This topic has expert replies
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

divisor?

by sanju09 » Tue Feb 24, 2009 4:58 am
When 242 is divided by a certain divisor the remainder obtained is 8. When 698 is divided by the same divisor the remainder obtained is 9. However, when the sum of the two numbers 242 and 698 is divided by the divisor, the remainder obtained is 4. What is the value of the divisor?

A. 11
B. 17
C. 13
D. 23
E. None of these
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Source: — Problem Solving |

Senior | Next Rank: 100 Posts
Posts: 71
Joined: Sat Sep 20, 2008 5:48 am
Thanked: 5 times

by willbeatthegmat » Tue Feb 24, 2009 5:09 am
According to the question, the divisor shud divide 242-8 = 234, 698-9= 689 & 936. Look for the number that divides all the 3 number evenly. Only option C-13 satisfies the condition.

User avatar
Master | Next Rank: 500 Posts
Posts: 319
Joined: Wed Feb 04, 2009 10:32 am
Location: Delhi
Thanked: 84 times
Followed by:9 members

Re: divisor?

by sureshbala » Tue Feb 24, 2009 5:14 am
sanju09 wrote:When 242 is divided by a certain divisor the remainder obtained is 8. When 698 is divided by the same divisor the remainder obtained is 9. However, when the sum of the two numbers 242 and 698 is divided by the divisor, the remainder obtained is 4. What is the value of the divisor?

A. 11
B. 17
C. 13
D. 23
E. None of these
Small concept.....

If A leaves remainder R1 when divided by D and B leaves remainder R2 when divided by D, the remainder when A+B is divided by D will be R1+R2 provided R1+R2 < D. In case if R1+R2 >D, it is further divided by D and the remainder is given.

Coming to our question, the remainder must be 8+9 = 17. But since it is given as 4, it is implied that 17 > our divisor and hence it is reduced to 4. So the divisor must be 13.