Answer: C) 4 Explanation: A square and a rectangle each have 4 right (90 deg) angles.  Both square and rctangle have 4 sides and 4 angles, but the only difference is square is a rectangle with all sides equal.

Answer: D) Sliding to Rolling Explanation: Any object rolls when there is no friction. So, Sliding to Rolling is correct.

The Double V Campaign was used in World War II. The purpose of the double v campaign is to fight for victory and ending segregation at home. It was aimed at African-Americans, and it first appeared in an African-American newspaper, the Pittsburgh Courier, in 1942. The Double V Campaign worked to have a victory over racism abroad and racism in the United States.It stood so it gave a chance for Black Americans to fight in the war so they could achieve Victory at Home and Abroad- (Civil Rights then the war in the Atlantic and Pacific).

Answer: A) Stupa Explanation: Stupa represents the symbol of death of Gautama Buddha. On the other hand, Bodhi Tree is the symbol of nirvana of Gautama Buddha.

Answer: B) 19/42 Explanation: A red ball can be drawn in two mutually exclusive ways  (i) Selecting bag I and then drawing a red ball from it.   (ii) Selecting bag II and then drawing a red ball from it.   Let E1, E2 and A denote the events defined as follows: E1 = selecting bag I, E2 = selecting bag II A = drawing a red ball Since one of the two bags is selected randomly, therefore  P(E1) = 1/2  and  P(E2) = 1/2 Now, PAE1 = Probability of drawing a red ball when the first bag has been selected = 4/7   PAE2  = Probability of drawing a red ball when the second bag has been selected = 2/6  Using the law of total probability, we have   P(red ball) = P(A) = PE1×PAE1+PE2×PAE2                              = 12×47+12×26=1942

Answer: A) 1 : 3 Explanation: Let the speed of the boat in still water is 'w' Speed of the current is 'c' Let the distance between two places is 'd' According to the question, motorboat takes half time to cover a certain distance downstream than upstream. dw+c = 12dw-c => 2w - 2c = w + c => w = 3c => c : w = 1 : 3   Hence, the ratio between rate of current(c) and rate of boat in still water(w) = 1 : 3

Answer: C) +4 Explanation: The given compound is NaHCO3 Sodium bicarbonate which is commonly known as Baking soda. Oxidation numbers are the charges on ions. When a neutral atom loses electrons it becomes positively charged. When a neutral atom gains electrons it becomes negatively charged.   Here the C represents the oxidation state of carbon in this compound. Compounds are electrically neutral, which is why we set the sum of the oxidation states equal to zero. Sodium has a +1 oxidation state. Hydrogen has a +1 oxidation state. Oxygen has a -2 oxidation state. There are three oxygen atoms, which means the total oxidation state provided by both oxygen ions is -6. Adding up these oxidation states we get: 1 + 1 + (-6) + C = 0 -4 + C = 0 => C = 4 This means the oxidation state of carbon in this compound is +4.

Answer: A) Diamond Explanation: Diamond is the hardest substance available on Earth. Diamond is the hardest substance available on Earth due to the giant molecular structure of diamond in which each carbon atom is covalently bonded to four other carbon atoms. A covalent bond is very strong and requires a large amount of energy to break itself, and diamond has many covalent bonds.