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: 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: 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: 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: 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

Answer: B) 29.39 cm Explanation: Volume of water flowing through 1 pipe of diameter x = Volume discharged by 6 pipes of diameter 12 cms.   As speed is same, area of cross sections should be same.    Area of bigger pipe of diameter x = Total area of 6 smaller pipes of diameter 12  i.e πR2 = 6πR12    Here R = R and R1 = 12/2 = 6    ⇒R2 = 6×6×6    R = 14.696    => D = X = 14.696 * 2 = 29.3938 cm.

Answer: C) China Explanation: China's amphibian aircraft, which is stated to be the world's largest, has successfully passed engine tests and is expected to make its maiden flight in the first half of the year 2017.