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.

You will get the answer in the riddle itself, if you read the riddle carefully. The riddle says "A cowboy arrives in town on Friday." So Friday is the name of the horse on which he comes. Hence, the only possibility is he arrives on the horse friday on Tuesday, stays for 3 days and leaves on the same horse on Friday.

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.

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.

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.

STARTLING is a required 9 letter English word is still a word each time you remove a letter from the word. And how it is shown below:    1. Remove the L, and the word becomes: STARTING 2. Remove one T, and the word becomes: STARING 3. Remove the A, and the word becomes: STRING 4. Remove the R, and the word becomes: STING 5. Remove the other T, and the word becomes: SING 6. Remove the G, and the word becomes: SIN 7. Remove the S, and the word becomes: IN 8. Remove the N, and the word becomes: I

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