Answer: B) 40 Explanation: Remaining work = 1 - 9/10 = 1/10   => A & B together completes 1/10 of work in 4 days   => 1 work can completed in ------ ? days   Let it be x days   =>  4110=x1   => x = 40 days.   Hence, A & B together can complete the work in 40 days.

Answer: D) All the above Explanation: Processes that require or give off heat will be limited to changes of state, known as phase changes, and changes in chemical constitution, or chemical reactions. Changes of state involve a solid melting, a liquid freezing, a liquid boiling or a gas condensing.   An exothermic process is one that gives off heat, which is transferred to the surroundings. An endothermic process is a reaction which heat has to be supplied to the system from the surroundings.   Here in all the given options, heat is taken away from them to change there phase.  Liquid to Solid --- Freezing Gas to Liquid --- Condensation Gas to Solid --- Deposition  are all examples of exothermic processes.

Answer: B) FALSE Explanation: False. Cube is not a Polygon. Because polygon is a two dimensional figure and can be drawn on a flat surface whereas Cube is three dimensional figure and cannot be drawn on a flat surface.

A solution is a homogeneous type of mixture of two or more substances. A solution has two parts:: 1. A solute and 2. A solvent.   The solute is the substance that dissolves, and the solvent is the majority of the solution.

Answer: D) 10 days Explanation: Ratio of efficiencies of Priya and Sai is Sai : Priya = 160 : 100 = 8 : 5 Given Priya completes the work in 16 days Let number of days Sai completes the work be 'd' => 5×16 = 8×d d = 10 days. Therefore, number of days Sai completes the work is 10 days.

Answer: B) 24 kmph Explanation: Total time taken = k/40 + 2k/20 hours = 5k/40 = k/8 hours Average speed = 3k/(k/8) = 24 kmph.

Answer: C) 30 m/s Explanation: The interval between object pass the same point is 4 sec. That means in 2 sec, object reaches the top and in next 2 sec, it again reaches the same point. By the info given, we can find the velocity of that point by using : v=u+(-gt) 0= u - 10×2 u = 20 Then the velocity at 25m is 20m/sec. so the initial velocity is -v2 = u2 + (-2gh)400 = u2 - 2x 10 x 25u2 = 900 => u = 30 m/s

Answer: D) Pascal Explanation: Pressure = (Net Force) / (Applied area) = Newton / square meters Measuring units of pressure are: . Pascal. Bar. Torr. Pounds per square inch (psi). Standard atmosphere (atm).