Answer: D) 180 Explanation: Given total number of cows = kNow, 1st son share = k/22nd son share = k/43rd son share = k/54th son share = 9 (k) + (k/4) + (k/5) + 9 = k=> k - (19k/20) = 9=> (20k-19k)/20 = 9=> k = 180.

Answer: C) 9 : 10 Explanation: The ratio of X and Y ages at present is 4:5.  Then, the ratio 20 years ago will not be more than the ratio at present. So, from the options 9:10 is not satifying => its ratio is 0.9 which is greater than presnt ratio of 0.8.

Answer: D) 125 Explanation: Methods for selecting 4 questions out of 5 in the first section = 5 x 4 x 3 x 2 x 1/4 x 3 x 2 x 1 = 5. Similarly for other 2 sections also i.e 5 and 5 So total methods = 5 x 5 x 5 = 125.

Answer: A) 10 Explanation: Given total rupees = 20 RsNo. of one rupee stamps = 3Now, remaining money = Rs. 17With that he buys only 2 and 5 rupee stampsLet number of Rs. 5 stamps = KLet number of Rs. 2 stamps = L5K + 2L = 17K = 3, L = 1 (possible)L = 6, K = 1 (possible)=> But given that they are different in number so, K is not equal to 3one rupee stamps = 32 two stamps = 65 rupee stamps = 1Total number of stamps = 10.

Answer: B) 105 Explanation: First line will cut all other 14, similarly second will cut 13, and so onTotal = 14+13+12+11+10+9+8+7+6+5+4+3+2+1 = 105.

Answer: C) 31.4208 and 62.8416 Explanation: Birds speeds in mtrs/sec is 'x' and '2x' .While flying from Engine to end, relative speed = (x+10) m/secfrom end to engine, flying speed = (2x - 10) mtr/secso 1000/(x+10) + 1000/(2x-10) = 187.5 secssolving it, we getso x = 8.728 m/sec and 2x= 17.456 m/sec x = 31.4208 km/hr and 2x = 62.8416 km/hr.

Answer: D) 26 Explanation: Let, Hema attempted 'k' sum correctly, then k x 3 -2 x(35-k) = 605k = 130k = 26 so 26 correct sums.

Answer: A) 264 Explanation: Let the number be 'x'. Then, from given data x/2 + x/3 + x/4 = x+2213x/12 = x+22x = 264