Answer : 1. "88572"
Explanation :

Answer: A) 88572 Explanation: Given a secret is told to 3 persons in 3 minutes.And if the process continues with each person saying 3 other persons,In 30 minutes => the rocess for 10 times because each person time is 3 minutes.Required number of persons = 3 + 32 + 33 + .... + 39 + 310   Now it forms a geometric progression,   Sum to n terms is S = arn - 1r - 1   Here a = 3, r = 3  => 59048 x 3 /2   = 88572.