Answer: D) Covalent bonds Explanation: Deoxyribose, which is a pentose, and a phosphate group are the two molecules together form the two sides of the DNA i.e, A sugar (deoxyribose) and a phosphate. DNA is a double-stranded molecule twisted into a helix (think of a spiral staircase). Each spiraling strand, comprised of a sugar-phosphate backbone and attached bases, is connected to a complementary strand by non-covalent hydrogen bonding between paired bases. The bases are adenine (A), thymine (T), cytosine (C) and guanine (G). A and T are connected by two hydrogen bonds. G and C are connected by three hydrogen bonds.

Answer: C) 81 Explanation: 729 = 9 x 9 x 9 => Cube root of 729 = 9   Now, required square of 9 = 9 x 9 = 81.

Answer: A) 22/7 x 24/35 Explanation: Since level of water increased in cylinder by height 4.  This is because of the rectangular block .   Therefore , area of rectangular block immersed in water is  = 227×6×6×4   Thats why portion of block immersed in water is  = (22/7 * 36 * 4) / total vol. of rectangle  = (22/7 * 36 * 4)/ (7*5*6)  = (22/7 * 24)/ 35.

Answer: B) 4 days Explanation: Given 10 men take 15 days to complete a work => Total mandays = 15 x 10 = 150 Let the work be 150 mandays. => Now 37 men can do 150 mandays in 150/37 =~ 4 days

Answer: A) 2893 Explanation: For solving this problem first we would break the whole range in 5 sections 1) From 1 to 9Total number of zero in this range = 0 2) From 10 to 99Total possibilities = 9*1 = 9 ( here 9 is used for the possibilities of a non zero integer) 3) From 100 to 999 - three type of numbers are there in this range a) x00 b) x0x c) xx0 (here x represents a non zero number)Total possibilities for x00 = 9*1*1 = 9, hence total zeros = 9*2 = 18for x0x = 9*1*9 = 81, hence total zeros = 81similarly for xx0 = 81 total zeros in three digit numbers = 18 + 81 +81 = 180 4) From 1000 to 9999 - seven type of numbers are there in this rangea)x000 b)xx00 c)x0x0 d)x00x e)xxx0 f)xx0x g)x0xxTotal possibilities for x000 = 9*1*1*1 = 9, hence total zeros = 9*3 = 27 for xx00 = 9*9*1*1 = 81, hence total zeros = 81*2 = 162 for x0x0 = 9*1*9*1 = 81, hence total zeros = 81*2 = 162for x00x = 9*1*1*9 = 81, hence total zeros = 81*2 = 162 for xxx0 = 9*9*9*1 = 729, hence total zeros = 729*1 = 729for xx0x = 9*9*1*9 = 729, hence total zeros = 729*1 = 729for x0xx = 9*1*9*9 = 729, hence total zeros = 729*1 = 729total zeros in four digit numbers = 27 + 3*162 + 3*729 = 2700thus total zeros will be 0+9+180+2700+4 (last 4 is for 4 zeros of 10000)= 2893

Answer: D) Felix Explanation: Here my name "Iron59" means Felix. Since my father is a chemist he gave code Iron for Fe as chemical symbol for Iron is Fe and my mother is a mathematician she gave 59 for Lix as Roman word for 59 is Lix.   Hence my name is FELIX.

Answer: A) Lose electrons and forms cations Explanation: When combining with nonmetallic atoms, metallic atoms generally will Lose electrons and forms cations.   As the ionization energy of te metals are very low, so they can easily lose electrons and form positively charged ion called cations.

Answer: A) Rs. 620 Explanation: Let the C.P of one item is Rs. P and that of other is Rs. (7500 - P) According to the data given C.P = S.P => Px(116/100) + (7500-P)x(86/100) = 7500 => 30P = 105000 => P = 3500 Required difference between selling prices = Rs. [(3500/100) x 116] - [(4000/100) x 86] = 4060-3440 = Rs. 620