All Courses
Explore Courses UPSC Exam UPSC Test Series Free Notes EduRev Infinity Get the App Login Join for Free
Sign in Open App
UPSC Exam  >  UPSC Questions  >  A and B walk around a circular track. They st... Start Learning for Free
SaveJoin the Discussion on the App
A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?
  • a)
    5
  • b)
    6
  • c)
    7
  • d)
    8
Correct answer is option 'C'. Can you explain this answer?
FREE This question is part of
Download PDF Attempt Test
Download PDF Attempt this Test
Verified Answer
A and B walk around a circular track. They start at 8 a.m. from the sa...
GIVEN ;-

⇒ A and B walk around the circular track

⇒ A and B starts to walk around the circular park but in opposite direction     
                                                                      =  9 a. m

⇒ A and B walk in the speed = 2 rounds/ hr and 3 rounds / hr


TO FIND ;-

⇒How many times shall they cross each other before 9.30 a.m.?


SOL ;-

⇒ Let us find their respective speed. -

Respective speed = Total speed of A + Total speed of B

                           =   2  +  3  = 5

So respective speed or  relative speed is equal to 5 rounds \ hr.

⇒ So by this statement we derive that A and B cross 5 times.

⇒
 Hence we can say that A And B cross 5 times in only 1 hr.

       
 A and B cross 2 times in 1 \ 2 hrs


Time lapse  between  8 a.m and 9.30 a.m is  1.5 hrs.


No. of times did A and B cross in 1  hr + No. of times did A and B cross in 1 \2 hrs =   

⇒ 5  +  2 = 7  times

⇒Answer ;-  Hence A and B cross 7 times 
 
View all questions of this test
Most Upvoted Answer
A and B walk around a circular track. They start at 8 a.m. from the sa...
Given data:
- The circular track is of unknown length.
- A and B start at 8 a.m. from the same point in opposite directions.
- A's speed = 2 rounds per hour.
- B's speed = 3 rounds per hour.
- Time duration = 1.5 hours (from 8 a.m. to 9.30 a.m.).
- We need to find out how many times A and B cross each other before 9.30 a.m.

Solution:
- We know that A and B are walking in opposite directions on a circular track.
- Hence, their relative speed = Speed of A + Speed of B = 2 + 3 = 5 rounds per hour.
- In 1 hour, they cover a distance of 5 rounds (as they are moving in opposite directions).
- In 1.5 hours, they cover a distance of 7.5 rounds.
- Now, we need to find out how many times they cross each other in 7.5 rounds.
- Let's assume that they cross each other 'n' times.
- When they cross each other, the distance covered by A + the distance covered by B = 1 round (as they meet at a point on the track).
- Hence, the total distance covered by A and B when they cross each other = n rounds.
- We can write this as:
Distance covered by A + Distance covered by B = n
(2x + 3x) = n (where x is the number of times they cover the track)
5x = n
- Now, we need to find out the value of x (i.e. the number of times they cover the track in 1.5 hours).
- The speed of A = 2 rounds per hour.
- Hence, in 1.5 hours, A covers a distance of 3 rounds.
- Similarly, the speed of B = 3 rounds per hour.
- Hence, in 1.5 hours, B covers a distance of 4.5 rounds.
- The total distance covered by A and B in 1.5 hours = 3 + 4.5 = 7.5 rounds.
- Hence, x = 1.5 (as they cover 5 rounds in 1 hour and 7.5 rounds in 1.5 hours).
- Therefore, the number of times A and B cross each other in 1.5 hours = n = 5x = 5 x 1.5 = 7.5.
- As they cannot cross each other half a time, the actual number of times they cross each other before 9.30 a.m. = 7 (since they cross each other 7 times in 1.5 hours).

Therefore, the correct answer is option 'C' (7).
< Previous Question Next Question >
Explore Courses for UPSC exam

Similar UPSC Doubts

Historically, the biggest Challenge to world agriculture has been to achieve a balance between demand for and supply of food. At the level of individual countries, the demand-supply balance can be a critical issue for a closed economy, especially if it is a populous economy and its domestic agriculture is not growing sufficiently enough to ensure food supplies, on an enduring basis; it is not so much and not always, of a constraint for an open, and growing economy, which has adequate exchange surplus to buy food abroad. For the world as a whole, supply-demand balance is always an inescapable prerequisite for warding off hunger and starvation. However, global availability of adequate supply does not necessarily mean that food would automatically move from countries of surplus to of deficit if the latter lack in purchasing power. The uneven distribution of hunger, starvation, under or mal-nourishment, etc., at the world-level, thus owes itself to the presence of empty-pock hungry mouths, overwhelmingly confined to the underdeveloped economies. In as much as ‘a two-square meal’ is of elemental significance to basic human existence, the issue of worldwide supply of food has been gaining significance, in recent times, both because the quantum and the composition of demand has been undergoing big changes, and because, in recent years, the capabilities of individual countries to generate uninterrupted chain of food supplies have come under strain. Food production, marketing and prices, especially price-affordability by the poor in the developing world, have become global issues that need global thinking and global solutions.Q. A and B walk around a circular park. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other after 8 00 a.m. and before 9.30. a.m.?

Six friends A, B, C, D, E and F went to a restaurant for dinner and are seated around a circular table. Three of them are vegetarians and the rest are non-vegetarians. The expense for the starter shared equally by them. The bill for main course was paid separately by each individual who ordered as per his/her choice. Further, the following details are known:1. There was one pair of vegetarians and one pair of non-vegetarians sitting opposite each other.2. C, a vegetarian who spent ₹200 for his dinner, was seated between two non-vegetarians, and was adjacent to neither B nor D.3. Each item in the main course at the restaurant varied from 100 to ₹200 (both including) and was a multiple of 20. Each of the friends ordered only one main course item.4. A common bill was presented after completion of dinner.5. A and E, who were sitting opposite each other, are either both vegetarians or both non-vegetarians,.6. B is opposite the person who paid the highest amount of ₹300.7. No two friends paid the same amount for the dinner. Each vegetarian main course item costed less than any non-vegetarian main course item.?

Eight persons P, Q, R, S, T, U, V and W- sit around a square table in which four persons face away from the center remaining four persons face the center but not necessarily in the same order. When two or more persons are said to be facing the same direction, it means that either all of them face the center or all of them face away from the center. When two persons are said to be facing different directions, it means that one of them is facing the center and the other one is facing away from the center. Four sit at the corners of the table and four sit at the middle of the sides. The following information is known about them.P sits to the immediate right of T as well as to the immediate right of V. Q does not sit at the corners. T and Q face the same direction and are in opposite positions. W and R sit adjacent to each other and one of them sits at the corners. P and U are facing each other. T and R are facing the same direction. Q sits to the immediate right of S. W does not sit adjacent to U.?

Top Courses for UPSCView all

Top Courses for UPSC

A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer?
Question Description
A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer?.
Solutions for A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for UPSC. Download more important topics, notes, lectures and mock test series for UPSC Exam by signing up for free.
Here you can find the meaning of A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer?, a detailed solution for A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?a)5b)6c)7d)8Correct answer is option 'C'. Can you explain this answer? tests, examples and also practice UPSC tests.
Explore Courses for UPSC exam

Top Courses for UPSC

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev
Get App
© EduRev
Education Revolution
Follow Us
Signup to see your scores go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup