Firstly, I focussed on "If you remove my 1st & 2nd letters, you can't see me". The first thing that comes to mind which we can’t see is the "AIR".   So now, what 4 letter words can be formed ending with "AIR"? Think of all the words from A to Z, considering which one lies above you. That is how we get to "HAIR".   Now, which 5 letter word can be formed ending with "HAIR"? Starting with A to Z, we reach "CHAIR" and also, it lies below us.   And the required answer is "CHAIR".

Answer: C) 80 Explanation: Let marks obtained by S = M R's marks = 0.80M Q's marks = 1.25 (0.80M) P's marks = (0.90) (1.25) (0.80M) = 0.9M But 0.9M = 360 M = ? M = 400 Hence % of marks obtained by S = 400/500 x 100 = 80%.

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: C) 2 Explanation: Total money decided to contribute = 750 x 12 = 9000 Let 'b' boys dropped The rest paid 150/- more => (12 - b) x 900 = 9000 => b = 2 Hence, the number of boys who dropped out is 2.

Answer: A) 400 Explanation: Let the total number of pages in the book be 'x'. From given data, 2x/5 + 34x/100 + 52 + 52 = x => 40x + 34x + 10400 = 100x => 26x = 10400 => x = 400. Hence, total pages in the book are 400.

Answer: B) 26 Explanation: Let the integer be x. Then,  x2-20x = 156   (x + 6)(x - 26) = 0   x = 26   The integer is 26.

Answer: D) None Explanation: As given Kapil's 8th birthday was celebrated 2 years ago, Kapil’s present age = 8 + 2 = 10 years. Father's age is twice of Kapil’s age after 10 years. => F + 10 = 2 (K + 10) = 2 (10+ 10)F = 30years, Avanthi's age =1/6(F) = 30/6 = 5 years.

Answer: D) Covalent- network Explanation: Graphite is a covalent-network type of crystalline solid.   There are two main categories of solids. 1. Crystalline solids and 2. Amorphous solids. Crystalline solids are those in which the atoms, ions, or molecules that make up the solid exist in a regular, well-defined arrangement. There are four types of crystalline solids : Ionic solids :— Made up of positive and negative ions and held together by electrostatic attractions. They’re characterized by very high melting points and brittleness and are poor conductors in the solid state. An example of an ionic solid is table salt, NaCl. Molecular solids :— Made up of atoms or molecules held together by London dispersion forces, dipole-dipole forces, or hydrogen bonds. Characterized by low melting points and flexibility and are poor conductors. An example of a molecular solid is sucrose. Covalent-network (also called atomic) solids :— Made up of atoms connected by covalent bonds; the intermolecular forces are covalent bonds as well. Characterized as being very hard with very high melting points and being poor conductors. Examples of this type of solid are diamond and graphite, and the fullerenes. As you can see below, graphite has only 2-D hexagonal structure and therefore is not hard like diamond. The sheets of graphite are held together by only weak London forces! Metallic solids :— Made up of metal atoms that are held together by metallic bonds. Characterized by high melting points, can range from soft and malleable to very hard, and are good conductors of electricity.