Answer: A) oxygen, nitrogen, carbon, hydrogen, sulfur, and phosphorus Explanation: Living organisms often contain trace amounts of several elements, but the most abundant ones are oxygen, carbon, hydrogen, nitrogen, calcium, sulphur and phosphorus.

Answer: A) 200 mts Explanation: Length of train A = 48 x 9 x 5/18 = 120 mts Length of train B = 48 x 24 x 5/18 - 120 => 320 - 120 = 200 mts.

Answer: D) a person who balances social, physical, and mental health Explanation: A person who balances all the three healths such as Physical, mental and Social healths has the best overall health.

Answer: B) 15 Explanation: Here crossing is AaBbCc x AaBbCc As it is trihybrid cross, we know, Number of zygotes formed = 4n, where n = 3 43 = 64 Given ratio of offsprings = 1 : 6 : m : 20 : m : 6 : 1 Now,  1 + 6 + m + 20 + m + 6 + 1 = 64 34 + 2m = 64 2m = 30 => m = 15.

Answer: C) 50 Explanation: Let the required number be 'p' 36 of what number is 18 implies 36% of p = 18 => 36 x p/100 = 18 => p = 1800/36 => p = 50.   Hence, 36% of 50 is 18.

Answer: C) Electron transport chain Explanation: There are 3 stages in cellular respiration. They are: 1. Glycolysis 2. Kreb's cycle 3. Electron transport chain   Here, Glycolysis produces only 2 ATP whereas Kreb's cycle produces no ATP. Electron transport chain of the cellular respiration produces the maximum ATP.

The answer is 'X'. 1. It is the 24th letter in the alphabetical order. 2. XX (20 in Roman) 3. XXX is used to refer dirty.

Answer: A) It is insoluble in ether and other Non-polar solvents Explanation: Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+ and hydroxide anions OH−. Properties: 1. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air. 2. NaOH is insoluble in ether and other non-polar solvents. 3. It is an odorless compound.   Uses: Sodium hydroxide is used in many industries: in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents, and as a drain cleaner.