Answer: A) 7 Explanation: As the work is sameM1D1 = M2D2 Here Let the number of men employed was M=> 11M = 7(M+4)=> 11M - 7M = 28=> M = 7

Answer: D) 81.5 Explanation: Let the number of students in classes A, B and C be P, Q and R respectively.Then, total score of A = 83P, total score of B = 76Q, total score of C = 85R.Also given that,(83P + 76Q) / (P + Q) = 79=>4P = 3Q.(76Q + 85R)/(Q + R) = 81=>4R = 5Q,=>Q = 4P/3 and R = 5P/3Therefore, average score of A, B, C = ( 83P + 76Q + 85R ) / (P + Q + R) = 978/12 = 81.5

Answer: C) Zn Explanation: In chemistry, a metal is an element that readily forms positive ions (cations) and has metallic bonds. Metals are opaque, lustrous elements that are good conductors of heat and electricity. Most metals are malleable and ductile and are, in general, denser than the other elemental substances.   Examples of metals are aluminium, copper, iron, tin, gold, lead, silver, titanium, uranium, and zinc.   Here Se - Selenium is an element but is not a metal, S - Sulphur is not a metal and I - Iodine is also not a metal.   Hence, Zn - Zinc is the only metal in the given options.

Answer: C) Fluorine Explanation: Electronegativity refers to the ability of an atom to attract shared electrons in a covalent bond. The higher the value of the electronegativity, the more strongly that element attracts the shared electrons. Electronegativity increases from bottom to top in groups, and increases from left to right across periods. Thus, fluorine is the most electronegative element and lithium is the least.

Answer: B) 40 sec Explanation: Speed of train relative to jogger = 45 - 9 = 36 km/hr.= 36 x 5/18 = 10 m/sec. Distance to be covered = 260 + 140 = 400 m. Time taken = 400/10 = 40 sec.

Answer: C) 13 days Explanation: Ratio of times taken by A and B = 100 : 130 = 10 : 13.Suppose B takes x days to do the work. Then, 10 : 13 :: 23 : x     =>     x = ( 23 x 13/10 )     =>     x = 299 /10. A's 1 day's work = 1/23 ;B's 1 day's work = 10/299 . (A + B)'s 1 day's work = ( 1/23 + 10/299 ) = 23/299 = 113 . Therefore, A and B together can complete the work in 13 days.

Answer: C) Planet Labs Explanation: American startup Planet Labs, that launches small satellites into orbit and sells the imagery, has announced its acquisition of Google's 'Terra Bella' satellite business. As part of the agreement, 60 Google employees will join the startup founded by ex-NASA scientists. Terra Bella, was acquired by Google in 2014 for $500 million and that time it was known as Skybox Imaging.

Answer: A) Rainfall Explanation: Savannas are home to a wide diversity of animals. Many animals of the savanna migrate throughout the year, searching for food and water. Many of the droughts are seasonal and hit one area before another, so animals are constantly following the rains.   Hence, Rain fall is what often governs animal migration on savannas.