Question

12 किमी लम्बे वृताकार मार्ग पर तीन धावक A.B.C एक ही बिन्द से तथा एक ही दिशा में क्रमश: 3
किमी/घंटा 7 किमी/घंटा तथा 13 किमी/घंटा की चाल से चलते हैं। कितने घंटे के उपरान्त वे
एक साथ मिलेंगे?
(8) 16 घंटे
(6)12 घंटे (6) 24 घंटे (d) 28 घंटे​

Answer 1

Step-by-step explanation:

Three runners a, b and c run along a circular path of 12 km long with speeds 3km/hr, 7km/hr, 13km/hr. They start their race from the same point for the same destination. After how much time they will meet again  

• So the long circular route is 12 km
• Now speed = distance / time  
• So time taken by A = 12 / 3 = 4 hours
• Time taken by B = 12 / 7 hours
• Time taken by C = 12 / 13 hours
• So we have 4, 12/7, 12/13
• Now LCM of Numerator / hcf of denominator.
•    So lcm of 4,12, 12 will be  
•    Factors are  
•       4 = 2 x 2
•      12 = 2 x 3 x 2
•       12 = 2 x 3 x 2
• So we get 2 x 2 x 3 = 12
• Now hcf of 7,13 will be 1
• So 12 / 1 = 12 hours.
• So they will meet again after 12 hours.

Reference link will be

https://brainly.in/question/18447314