Three friends Raju , Ramesh and Sunil start running around a circular stadium and complete a single round in 24 s, 36 s and 40 s, respectively. After how many minutes will they meet against at the sta

• A. 7 minutes
• B. 6 minutes
• C. 8 minutes
• D. 5 minutes

Answer: (B)

24 = 3 × 2 × 2 × 2 = 3 × 2³              36 = 3 × 3 × 2 × 2 = 3² × 2²and 40 = 2 × 2 × 2 × 5 = 5¹ × 23            LCM of 24, 36 and 40 = 3² × 2³ × 5                                         = 9 × 8 × 5 = 360Hence, they will meet again at the starting point after 360 s, i.e., 6 min