Home




How to Solve GMAT Clock Angle Problems

GMAT Clock ProblemsClock based math problems are among the most challenging and interesting problems to crack.

Basics
  
For every 60 units that a minute hand move in an hour , the hour hand moves 5 units.

For 12 hours the hour hand completes 360 degrees

1 hour  =  360/12 = 30 degrees
60 minutes = 30 degrees
Degrees turned by hour hand in 1 minute = 0.5 degrees

For 1 hour the minute hand completes 360 degrees

1 hour = 360 degrees
60 minutes = 360 degrees
Degrees turned by minute hand in 1 minute = 6 degrees

Lets test what we have learned:

Q) Find the degree between hour hand and minute hand at 3:32'

Hour hand = 3

1 minute ( hour hand) = 0.5 degrees
3 hours = 3*0.5*60(1 hour= 60 minutes)
3 hours ( 3'o clock) = 90 degrees

Minute Hand = 32'

1 minute(minute hand) = 6 degrees
32 minutes(minute hand) = 32*6 = 192 degrees

For the 32 minutes, the hour hand moves by an additional 16 degrees
 = 32*0.5

So Hour hand at 32 minutes = 90+16=106 degrees

Degrees between minute hand and hour hand at 3:32' = 192-106
=86 degrees

Number of right angles

1) A clock makes two right angles between 2 hours
2) The clock does not makes 48 right angles in 24 hours( 1 day)

P.S: Between 2 -4 and 8-10 there are 3 right angles and not 4

The first right angle between 3 - 4 (9-10)  and second right angle bw:
2-3(8-9) are the same.

Q) At what time between 3 and 4 p.m is the first right angle formed

At 3 p.m

 No of units that the hour hand is ahead of the minute hand = 15 units
 For 90 degrees the minute hand should be 15 units ahead of hour hand
 No of units that the minute hand has to cover = 15+15 = 30 units

Distance covered by minute hand over hour hand in one hour = 55 units
1 hour = 55 units
x hour = 30 units

x = 30/55 = 6/11 of an hour

So first right angle between 3 and 4 is at 6/11 of an hour
Converting 6/11 to minutes = 6/11 * ( 60) minutes
                              = 360/11 minutes
                              = 32 ( 8/11) minutes
Converting 8/11 minutes to seconds = 8/11*(60) = 480/11 = 43.6363..

So the first right angle is at 3 : 32 : 43.64

Learn how to Solve Tricky Clock Angle Math Problems

Essential GMAT Reading Comprehension Guide


After reading F1GMAT’s Essential GMAT Reading Comprehension Guide, you will:

1. Complete GMAT RC Questions in less than 1 minute and 50 seconds
2. Read Faster
3. Take Notes Effectively
4. Collect and Interpret Facts
5. Speed up Summary Creation
6. Remember Information
7. Question the Author   
8. Learn to Answer GMAT Reading Comprehension Title question   
9. Learn to Answer GMAT Reading Comprehension Main Idea Question   

10.Learn to Answer GMAT Reading comprehension Inference question

11. Learn to Answer GMAT Reading Comprehension Detail Question   

12. Learn to Answer GMAT Reading Comprehension Purpose Question
12. Learn to Answer GMAT organization of passage Question
13. Learn to identify the style/tone or attitude of the author

Download Essential GMAT Reading Comprehension Guide (2019 Edition) (100+ New Questions)









Mastering GMAT Critical Reasoning



After you read F1GMAT’s Mastering GMAT Critical Reasoning Guide, you will learn:

How to overcome flawed thinking in GMAT Critical Reasoning?  


How to spot Inconsistencies in Arguments  

How to eliminate out of scope answer choices using Necessary and Sufficient Conditions  

How to Paraphrase GMAT Critical Reasoning Question  

How to Answer Assumption Question Type  

How to Answer Conclusion Question Type  

How to Answer Inference Question Type  

How to Answer Strengthen Question Type  

How to Answer Weaken Question Type  

How to Answer bold-faced and Summary Question Types  

How to Answer Parallel Reasoning Questions  

How to Answer the Fill in the Blanks Question


Download Mastering GMAT Critical Reasoning (2019 Edition) (25+ New Questions)




Navigate F1GMAT


F1GMAT Services (MBA Applicants) 


F1GMAT's Books

MBA Salary(Latest Salary Data)
 
MBA Admission Interview Tips

Funding 

Deadlines

MBA Application Essays


MBA Recommendation Letter

GMAT Tutorials

GMAT Question Bank

Top MBA Programs

Get F1GMAT's Newsletters (Best in the Industry)
Included in the Newsletter:

  • Ranking Analysis
  • Post-MBA Salary Trends
  • Post-MBA Job Function & Industry Analysis
  • Post-MBA City Review
  • MBA Application Essay Tips
  • School Specific Essay Tips
  • GMAT Preparation Tips
  • MBA Admission Interview Tips
  • School Specific Interview Tips
  • Funding Guidance and
  • Special Consultation Service (only for Subscribers)

Subscribe to F1GMAT's Newsletter