Answer: C) Thunder Explanation: The Sound Following the flash of lighting is because of Thunder.   Lightning is seen earlier than thunder because light travels much faster than sound.   The roar of thunder is the result of a shock wave produced when lightning super-heats the air through which it passes, causing that air to expand very rapidly. This rapid expansion of air creates a shock wave that travels outward at close to the speed of sound.

Answer: D) Graphical User Interface Explanation: GUI stands for Graphical User Interface.   A Graphical User Interface is a computer interface that allows users to interact with a device through graphical elements such as pictures and animations, as opposed to text-based commands.

Answer: B) 1.5 Explanation: Given Five boxes of bananas sell for Rs. 30. => 1 Box of Bananas for = 30/5 = Rs. 6   Then, for Rs. 9 => 9/6 = 3/2 = 1.5   Hence, for Rs. 9, 1.5 box of bananas can buy.

Answer: D) 100% Explanation: When 3 passengers income was 3xexpense= Rs.30 profit =20% of 30 = Rs.6 That means his earning is Rs.36. so that per passenger fare must be Rs.12. When 4 passengersearning = 12x4=Rs.48.expense =Rs.24.profit = Rs.24 = 100%

Answer: A) Hydrogen sulphide Explanation:

Answer: D) All the above Explanation:

Answer: A) 50 yrs Explanation: Let age of retirement = Sso according to the given condition 25000(x-20)=10000 x 3 + 12000 + 14000 + 16000 + 18000 + 20000 + 22000 + 24000 + 26000 + 28000 + 30000 + 30000(S-33)= 30000 + 210000 + 30000S-990000= 30000S - 750000or 25000S - 500000 = 30000x - 750000or 5000x = 250000or S = 50 yrs.

Answer: C) 35 days Explanation: Distance d = 1200kmlet S be the speed he walks 15 hours a day(i.e 24 - 9)so totally he walks for 70 x 15 = 1050hrs. S = 1200/1050 => 120/105 = 24/21 => 8/7kmph given 1 1/2 of previous speedso 3/2 * 8/7= 24/14 = 12/7 New speed = 12/7kmph Now he rests 10 hrs a day that means he walks 14 hrs a day. time = 840 x 7 /12 => 490 hrs=> 490/14 = 35 days So he will take 35 days to cover 840 km.