Answer: D) 21 Explanation: Total number of exams written by 100 students = 48 + 45 + 38 = 131Now let us say x members are writing only 1 exam, y members are writing only 2 exams, z members are writing only 3 exams.Therefore, x + 2y + 3z = 131 also x + y + z = 100.Given that z = 5. So x + 2y = 116 and x + y = 95.Solving we get y = 21.So 21 members are writing exactly 2 exams.

Answer: B) radon Explanation: The seven elements — helium, neon, argon, krypton, xenon, radon, and oganesson of Group 18 of the periodic table are Noble or Inert gases.   Radon is the heaviest and Helium is the lightest gases of the noble gases.

Answer: A) 40 kms Explanation: Let the actual distance travelled be x km. Then x/8=(x+20)/12 => 12x = 8x + 160=> 4x = 160=> x = 40 km.

Answer: D) The dacoits having stopped for dividing the booty, the police overtook them Explanation: As it is the past continuous sentence.

Answer: C) 2 Explanation: Here the most stable carbocation is the option (2).   Carbocations are always hungry for electrons. The stability of carbocations increases from primary to secondary to tertiary. Here, option (c) shows the most stable carbocation because it can easily withdraw electrons from two other carbon atoms and the more electronegative oxygen atom.   Carbocation stability depends on hyperconjugation. The tertiary carbocation is stabilized by electron releasing inductive effect.

Answer: D) Brahmaputra and Indus Explanation:

Answer: D) Cancellous bone Explanation: Spongy, porous bone tissue is also called cancellous bone.   Cancellous bone is found in bones that aren't generally under significant stress like in the shoulder blades, ribs, parts of the skull, and at the ends of long bones.

Answer: D) Rs. 1530 Explanation: Ratio of investments of A, B & C => Share of C = 1530 Share of B = 765 Share of A = 1020