Answer: A) W Explanation: W is the symbol for chemical element Tungsten or Wolfram. It is used in making filaments of bulbs.

Answer: C) train Explanation: Train becomes trail when the "n" is replaced by an "l", and grain becomes grail when the "n" is replaced by an "l".

Answer: A) Tooth Enamel Explanation: Tooth Enamel is the hardest and most highly mineralized substance in the human body. It is a tissue and not a bone. This tissue has high mineral content which makes it hardest substance.   Femur and Temporal bone of the skull are the hardest bones of the human body.

Answer: B) Individual liberty Explanation:

Answer: A) Michael Faraday Explanation: Michael Faraday invented Electric Generator in 1831.   The operating principle of electromagnetic generators was discovered in the years of 1831–1832 by Michael Faraday.   The principle later called Faraday's law, is that an electromotive force is generated in an electrical conductor which encircles a varying magnetic flux.

Answer: A) 5:1 Explanation: Let the speed of the man in still water = p kmph Speed of the current = s kmph Now, according to the questions (p + s) x 10 = (p - s) x 15 2p + 2s = 3p - 3s => p : s = 5 : 1   Hence, ratio of his speed to that of current = 5:1.

Answer: D) 144 Explanation: Given ratio of pens and pencils = 3 :2 Number of Pens = 3x Number of Pencils = 2x Average number of pencils & Pens = 3x + 2x2 = 180 5x = 360 => x = 72 Hence, the number of pencils = 2x = 72 x 2 = 144.

Answer: C) Nuts Explanation: