Answer: C) 6 Explanation: ?2 = 2×78-21+8+49-148= 57 - 21=36=> ? = ±6

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: C) 10^7 ergs Explanation: 1 Joule = 107 ergs = 0.000239 Kilo Calories. Joule is the Unit of Energy. Joule is equal to Energy transferred to an object when a force of One Newton acts on that object in the direction of its motion through a distance of one metre.(1 N-m)

Answer: A) 3:2 Explanation: Concentration of glucose are in the ratio = 12:35:45 Quantity of glucose taken from A = 1 liter out of 2 Quantity of glucose taken from B = 3/5 x 3 = 1.5 lit Quantity of glucose taken from C = 0.8 lit So, total quantity of glucose taken from A,B and C = 3.6 lit So, quantity of alcohol = (2 + 3 + 1) - 3.6 = 2.4 lit Ratio of glucose to alcohol = 3.6/2.4 = 3:2

Answer: B) 420 Explanation: Given total number of students in the class = 21   So each student will have 20 greeting cards to be send or receive (21 - 1(himself))   Therefore, the total number of greeting cards exchanged by the students = 20 x 21 = 420.

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: C) 70000 Explanation: 112 × 54112 × 1024= 112 × 1000024= 1120000/16 = 70,000.

Answer: D) Central Bank of India Explanation:   First Bank to introduce Credit Card in India - Central Bank of India First Bank to introduce ATM  -  HSBC, 1987 First Bank to introduce Internet Banking - ICICI Bank First Bank to introduce Mutual Funds - State Bank of India