Answer: A) 1009 Explanation: Given total number of rats = 999919   999919 = 1000000 - 81 = 10002 - 92 = (1000+9)(1000-9) = 1009 x 991.Since there were more rats than there were cats, 991 cats killed 1009 rats each.

Answer: D) all a, b and c Explanation:

Answer: D) February 28 Explanation: National Science Day is celebrated in India on 28 February each year to mark the discovery of the Raman effect by Indian physicist Sir Chandrashekhara Venkata Raman on 28 February 1928.

Answer: B) 720 Explanation: Let last digit is 2when second last digit is 4 remaining 4 digits can be filled in 120 ways, similarly second last digit is 6 remained 4 digits can be filled in 120 ways.so for last digit = 2, total numbers=240   Similarly for 4 and 6When last digit = 4, total no. of ways =240and last digit = 6, total no. of ways =240so total of 720 even numbers are possible.

Answer: A) Paging Explanation: Paging is a memory management technique in which process address space is broken into blocks of the same size called pages.

Answer: C) 3:2 Explanation: Let us assume S as number of shirts and T as number of trousersGiven that each trouser cost = Rs.70 and that of shirt = Rs.30Therefore, 70 T + 30 S = 810=> 7T + 3S = 81......(1)T = ( 81 - 3S )/7 We need to find the least value of S which will make (81 - 3S) divisible by 7 to get maximum value of TSimplifying by taking 3 as common factor i.e, 3(27-S) / 7In the above equation least value of S as 6 so that 27- 3S becomes divisible by 7 Hence T = (81-3xS)/7 = (81-3x6)/7 = 63/7 = 9 Hence for S, put T in eq(1), we getS = 81-7(9)/3 = 81-63 / 3 = 18/3 = 6.The ratio of T:S = 9:6 = 3:2.

Answer: B) Rs. 3 Explanation: Let wholesaler dealers marked price = 100%, Retailer's C.P = 80% And the retailer sells at 5% less than the marked price => S.P = 95%If S.P of 95% of the retailer costs Rs.19 to customer,so its C.P of 80% will cost 80 x 19/95 = 16 Profit made by the retailer = 19-16 =  Rs.3

Answer: D) 165 Explanation: Ratio C1:C2 = 3:5 and C2:C3 = 7:11So C1:C2:C3 = 21 : 35 : 55Let the strength of three classes are 21x, 35x and 55x respectively, then Given that 21x + 35x + 55x = 333=> 111x = 333 or x=3So strength of the class with highest number of students =55x = 55x3 = 165.