Answer: A) 49.6% Explanation: As these three strategies P, Q and R are independent so these will cut cost one after the other.If initial cost is Rs 100, then20% cost is cut after initializing strategy P, then cost will remain 80% = 80further 30% cost is cut after strategy Q, then cost will remain 70% of 80 = 56further 10% cost is cut after strategy R, then cost will remain 90% of 56 = 50.4 Thus final cost remains 50.4 % of the original cost. Hence net saving is 100 - 50.4 = 49.6 %.

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.

Answer: A) 4/3 days Explanation: Let the total number of documents to be printed be 12.  The number of documents printed by P in 1 day = 4.  The number of documents printed by Q in 1 day = 3.  The number of documents printed by R in 1 day = 2.  Thus, the total number of documents that can be printed by all the machines working simultaneously in a single day = 9.   Therefore, the number of days taken to complete the whole work = 12/9 = 4/3 days.