Answer: C) 60 kmph Explanation: Speed on return trip = 150% of 50 = 75 km/hr. Average speed = (2 x 50 x 75)/(50 + 75) = 60 km/hr.

Answer: A) 2Mg + O2 ----> 2MgO Explanation: Given Equation is  Mg + O2 → MgO Balancing the Chemical Equation is nothing but Conservation of Matter. As Matter is Neither created nor Destroyed, it must be conserved. Here we have 1 Mg and 2 O on the left side and 1 Mg and 1 O on the right side To balance that, add 1 Mg on the left side so that it becomes 2 Mg and 2 O on the left side i.e, 2 Mg + O2 → 2 MgO Here it has 2 Mg & 2 O on the left side and 2 Mg and 2 O on the right side and the Chemical equation is Balanced.

Answer: D) 36 years Explanation: Let present ages of Sushanth = w, Krish = x, Rishi = y and Rohit = z , thenw + x + y = 43 x 3 = 129 ---(i) andw + y + z = 49 x 3 = 147 ---(ii)Subtracting (i) from (ii), (w+y+z) - (w+x+y) = 147 - 129 , z - x = 18 ---(iii)Given Rohit's age=z=54, so from (iii), x = 54 - 18 = 36.Therefore, Krish age is 36 years.

The correct answer is the Glyptal. The term "natural polymers" refers to compounds that are produced naturally. Glyptal is a synthetic polymer and does not exist in nature. The polymer substance formed from glycerol and phthalic acid is known commercially as glyptal.

Answer: B) United States Explanation: The United States Constitution, ratified June 21, 1788, was influenced by the writings of Polybius, Locke, Montesquieu, and others. The document became a benchmark for republicanism and codified constitutions written thereafter. The Polish–Lithuanian Commonwealth Constitution was passed on May 3, 1791.