Answer: C) Magnesium nitrate Explanation: Mg(NO3)2 is Magnesium nitrate.   In the case of Mg(NO3)2, the metal in the compound is magnesium (Mg), and the non-metal here is called the nitrate ion (NO3). This makes the name of the compound simply magnesium nitrate.

Answer: C) 9 : 10 Explanation: The ratio of X and Y ages at present is 4:5.  Then, the ratio 20 years ago will not be more than the ratio at present. So, from the options 9:10 is not satifying => its ratio is 0.9 which is greater than presnt ratio of 0.8.

Answer: B) Rs. 11,250 Explanation: Given that SP = Rs. 12000 - 10%  = Rs. 10,800 Loss% = 4 We know that, C.P = 100/(100 - Loss%) x 100 => 100/100-4 x 10800 => 1080000/96 C.P = Rs. 11,250

Answer: C) 22 nd March Explanation:

Charles Babbage, the father of computer, invented the first general-purpose computer in an effort to prevent the mathematical errors that were prevalent in the human-calculated mathematics of his time.

Pace Count is a way to measure to Ground Distance. Pace Count is nothing but regular single natural step of about 30 inches long.

Answer: D) 120 Explanation: In given word OLIVER there are 3 vowels E, I & O. These can be arranged in only one way as dictionary order E, I & O.   There are 6 letters in thegiven word.   First arrange 3 vowels.   This can be done in 6C3 ways and that too in only one way.(dictionary order E, I & O)   Remaining 3 letters can be placed in 3 places = 3! ways   Total number of possible ways of arranging letters of OLIVER = 3! x C36 ways = 6x5x4 = 120 ways.

Answer: A) Air Explanation: Light travels fastest in Vacuum. The fastest thing in the whole universe is the speed of light in a vacuum like outer space. It is about 2.99 x 108 m/s.