therefore as Sunil halves his speed the time required to complete the round will double therefore time required for Round 1 = 2 mins Round 2 = 4 mins Round 3 = 8 mins Round 4 = 16 mins Round 5 = 32 mins Round 6 = 64 mins Round 7 = 128 mins Round 8 = 256 mins Round 9 = 512 mins time required by Anil for Round 1 to Round 9 = 1 mins Therefore the number of times they meet between 6th round and 9th round of Sunil (6th and 9th round is excluded) = time required by Sunil to complete round 7 and 8 - time required by Anil to complete his round 7 and 8 =256+128−1−1 =382 Therefore answer is option 'C'