Answer: B) 13 years Explanation: Given R + S + M + D = 76 => R+7 : S+7 : M+7 : D+7 = 7:6:5:8 => Let the ratio = x => M+7 = 5x => M = 5x-7 => R = 7x-7 => S = 6x-7 => D = 8x-7 => R + S + M + D = 76 => 7x-7 + 6x-7 + 5x-7 + 8x-7 = 76 => 26x - 28 = 76 => 26x = 104 => x = 4 => Mahesh's present age = 5x-7 = 20 - 7 = 13 years.

Answer: C) 289 Explanation: Here the given number series is 270, 261, 279, 252, 289, 243 270 - 9 = 261 261 + 18 = 279 279 - 27 = 252 252 + 36 = 288 (not equals to 289) 288 - 45 = 243   Hence, the odd number in the given number series is 289.

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: A) Oxygen and Acetylene Explanation: Normal Gas welding use oxygen-acetylene.   Depending on what materials you are welding, there are some more options that might be used. For example - MIG/TIG use Argon, MAG use an argon-something mix.

Answer: A) 7 Explanation: Given (3 Men + 4 Women + 6 Children) -----> 9 days But W = 2M and C = M/2 Now, convert Men and Children into Women by 3W2 + 4W + 6W4=> 32 + 4 + 32 = 7 Women  Therefore, 7 women alone can complete this work in 9 days.

Answer: B) Skype is an example of VoIP software. Explanation: VOIP is an acronym for Voice Over Internet Protocol, or in more common terms phone service over the Internet. Voice over Internet Protocol is a category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls by sending voice data in packets using IP rather than by traditional circuit transmissions of the PSTN.

Answer: C) Arrogant Explanation: Here the given words Careful and Cautious are related in such a way that they are Synonyms of each other. Therefore, Similarly Boastful is synonym to the word Arrogant. Happily and Humble are Antonyms of Boastful and Surprisingly is the word not related to Boastful in any way.   So, Careful is to Cautious as Boastful is to Arrogant.

Answer: B) 315 Explanation: Parallelograms are formed when any two pairs of parallel lines (where each pair is not parallel to the other pair) intersect.   Hence, the given problem can be considered as selecting pairs of lines from the given 2 sets of parallel lines.   Therefore, the total number of parallelograms formed = 7C2 x 6C2 = 315