Digit question

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 39
Joined: Mon Feb 08, 2010 12:41 pm

Digit question

by Lookingfor700GMAT » Sun Mar 07, 2010 9:41 am
I just went through the following question in the OG (12th ed). Please let me know how I would know that 6/11 is 0.54545454 in decimal form without a calculator. Is there a trick to know this? I know that is is roughly 54% but I wouldn't have known that the two digits of 5 and 4 are reoccuring.

What is the 25th digit to the right of the decimal point in the decimal form of 6/11?

3
4
5
6
7

The answer is 5.

User avatar
Community Manager
Posts: 1537
Joined: Mon Aug 10, 2009 6:10 pm
Thanked: 653 times
Followed by:252 members

by papgust » Sun Mar 07, 2010 5:43 pm
You need to perform long division to determine the recurring digits while dividing. Long division is a basic traditional method of dividing.

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7223
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Tue Mar 27, 2018 10:39 am
Lookingfor700GMAT wrote:I just went through the following question in the OG (12th ed). Please let me know how I would know that 6/11 is 0.54545454 in decimal form without a calculator. Is there a trick to know this? I know that is is roughly 54% but I wouldn't have known that the two digits of 5 and 4 are reoccuring.

What is the 25th digit to the right of the decimal point in the decimal form of 6/11?

3
4
5
6
7
6/11 = 0.545454...

We see that all the odd-numbered digits (1st, 3rd, etc.) to the right of the decimal point are 5 and all the even-numbered digits (2nd, 4th, etc.) to the right of the decimal point are 4. Since 25 is odd, the 25th digit to the right of the decimal point is 5.

Answer: C

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage