Answer: A) +6 Explanation: In H2SO4, Hydrogen has a charge of +2, with each hydrogen has +1. Oxygen has  a charge of -8, with each oxugen has -2. Total charge = (2 - 8) = -6 Therefore, the Oxidation number of Sulphur S is '+6' because to make the compound stable.

Answer: A) Biosphere Explanation: A biosphere is the sum of all the ecosystems established on planet Earth. An ecosystem is an area in which the plants and animals all interact to create a living environment. Therefore ecosystem is a smaller unit of earth, all ecosystems together form the earth.

Answer: D) Tata Steel and Wipro Explanation: Two Indian companies, Tata SteelBSE and Wipro have been named in the list of world’s most ethical companies by American think tank Ethisphere Institute. Ethisphere honors those companies who recognize their role in society to influence and drive positive change in the business community and organizations around the world. In 2017, 124 honorees were spanning five continents, 19 countries, and 52 industry sectors. Wipro is one of the two information technology companies named in the list, the other being Xerox Corporation.

Technically or logically it is possible only once. As if you subtract 5 from 25 at first te result will be 20. Now, you can't subtract 5 from 25 since the left number is 20.   But if you go mathematically, it can be done infinite times and only 5 times without going into the negatives.

Answer: C) O @ N # M Explanation:  O @ N # M means O is the father of N who is the sister of M i.e. O is a father of two children.

Answer: C) [6 + (261/315)] days Explanation: After day 1, A finishes 1/9 of the work. After day 2, B finishes 1/7 more of the total work. (1/9) + (1/7) is finished. After day 3, C finishes 1/5 more of total work. Total finished is 143/315. So, after day 6, total work finished is 286/315.   Now remaining work =  29 /315   On day 7, A will work again    Work will be completed on day 7 when A is working. He must finish 29/315 of total remaining work.   Since he takes 9 days to finish the total task, he will need 261/315 of the day.    Total days required is 6 + (261/315) days.

What has 4 Eyes But cannot see is Mississippi. The wording of Mississippi has 4 'i''s. But it can't see.

Answer: D) 26.88 Explanation: Given series follows the rule of 1050/2.5 = 420420/2.5 = 168168/2.5 = 67.2so 67.2/2.5 = 26.88