Latest TCS Aptitude Question SOLUTION: ) In a circular racetrack of length 100 m, three persons A, B and C start together. A and B start in the same direction at speeds of 10 m/s and 8 m/s respectively. While C runs in

• Placement Papers
• /
• TCS
• /
• Numerical Ability
• /
• Time Distance and Speed

TCS Question Papers: TCS Interview Experience(90) TCS Company Profile

(#M40040545) TCS Numerical Ability question time Keep an EYE

) In a circular racetrack of length 100 m, three persons A, B and C start together. A and B start in the same direction at speeds of 10 m/s and 8 m/s respectively. While C runs in the opposite direction at 15 m/s. When will all the three meet for the first time on the track after the start?
a) After 4 s
b) After 50 s
c) After 100 s
d) After 200 s
e) None of these

Asked In TCS ANUP KUMAR GUPTA (9 years ago)

Solved namrata singh Read Solution (13)

Is this Puzzle helpful?   (5)   (4) Submit Your Solution Time Distance and Speed

Read Solution (13) :

namrata singh  (9 years ago) Best Solution

A takes (100m) / (10m/s) = 10s to finish one complete round.
B takes (100m) / (8m/s) = 12.5s to finish one complete round.
C takes (100m) / (15m/s) = (20/3)s to finish one complete round.
For them to meet, the time will be LCM of above three times i.e,
LCM(10,12.5,20/3) = LCM(10,25,20)/GCD(1,2,3)=100/1=100sec

Is this solution Helpfull? Yes (44) | No (7)  

Surit Datta  (9 years ago)

After 100 sec
the option is c
am i ri8 or am i ri8??

Is this solution Helpfull? Yes (6) | No (19)  

ANIMESH GORAI  (9 years ago)

a) after 4 sec
in 4 sec a and b goes 40 m and 32 m
while in 4 sec c goes 60 sec in opposite direction
so total(40+60)m is coverd in 4 sec by a and c together

Is this solution Helpfull? Yes (2) | No (4)  

Anuj Yadav  (9 years ago)

working backword from the option
option a :

A=>4*10)=40m
B=>(4*8)=32m
C=>(4*15)=60m...........so here distance travelled by each person is not a Multiple of 100

So option c is correct
Answer is C)After 100s

Is this solution Helpfull? Yes (1) | No (2)  

Jay  (9 years ago)

Since the track is a circular track A and B will meet every 50 seconds. i.e. 100 / (10-8).
Since it is a multiple of 50 they will be meeting at the starting point every 50 Seconds.
If you multiply 15 x 50 you will get 750 and after the second 50 it will be 1500.
All of them will meet at the starting point after 100s

Is this solution Helpfull? Yes (1) | No   

Srinanda Nandy  (9 years ago)

after 100sec

Is this solution Helpfull? Yes | No (1)  

DEDEEPYA J  (9 years ago)

How ? will You explain the answer ?

Is this solution Helpfull? Yes | No   

ANUPRIYA GUPTA  (9 years ago)

Ans: After 100s

Is this solution Helpfull? Yes | No   

Siddhant Modi  (9 years ago)

both c and d are corrrect

Is this solution Helpfull? Yes | No (1)  

Avanthi Kareti  (9 years ago)

Ans : 200s , 100Sec is starting time. 200 sec is correct first time after the start

Is this solution Helpfull? Yes | No   

ASHWIN SONEKAR  (9 years ago)

According to formula :
time taken to meet for the first time= LCM of{100/(15-8) , 100/(15-10)}
= LCM of{100/7 , 100/5}
{LCM of 100 is =100 and HCF of 7 and 5 is=1}
so, =100/1
=100 sec
100 sec is the final ans

Is this solution Helpfull? Yes | No   

Saumashankar Bala  (7 years ago)

after 100s

Is this solution Helpfull? Yes | No   

Soundesh  (5 years ago)

Diff speed a and b is 2
Opsitr speed a and c is 25
Opsite speed b and c is 23
A and b meet 400 m meet
In this case c oppsite so
25×23=575
575m meets a,b and c 575×4 =2300m
575÷8
71.875 least so above 50 s

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.