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: 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: 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) Connective Explanation: There are four types of tissue in human body. They are    1.Muscular2.Connective3.Epithelial4.Nervous   Among these Connective Tissue are most abundant in our body.    CONNECTIVE TISSUE   Functions:   1) Wraps around and cushions and protects organs2) Stores nutrients3) Internal support for organs4) As tendon and ligaments protects joints and attached muscles to bone and each other5) Runs through organ capsules and in deep layers of skin giving strength   The 3 Elements of Connective Tissue:1) Ground substance – gel around cells and fibers2) Fibers – provide strength, elasticity and support3) Cells   There are 2 Kinds of Connective Tissue:   1) Loose Connective Tissue: a) Areolar Connective Tissue – cushion around organs, loose arrangement of cells and fibers. b) Adipose Tissue – storehouse for nutrients, packed with cells and blood vessels c) Reticular Connective Tissue – internal supporting framework of some organs, delicate network of fibersand cells   2) Dense Connective Tissue: a) Dense Regular Connective Tissue – tendons and ligaments, regularly arranged bundles packed with fibersrunning same way for strength in one direction. b) Dense Irregular Connective Tissue – skin, organ capsules, irregularly arranged bundles packed with fibersfor strength in all directions.

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.