Answer: B) 392 Explanation: The sum of the digits in 708, 618 and 816 is 15, but not in 392.

Answer: B) 117 Explanation: Square units 13 by 9 of an office means office of length 13 units and breadth 9 units.   Now its area is 13x 9 = 117 square units or units square.

Answer: C) 8, 4 Explanation: Let the number of girls = x => x + x + 4 = 12 => 2x = 8 => x = 4 => Number of girls = 4 => Number of boys = 4 + 4 = 8

Answer: A) 50 days Explanation: 50 men can build a tank in 40 days  Assume 1 man does 1 unit of work in 1 day Then the total work is 50×40 = 2000 units   50 men work in the first 10 days and completes 50×10 = 500 units of work 45 men work in the next 10 days and completes 45×10 = 450 units of work 40 men work in the next 10 days and completes 40×10 = 400 units of work 35 men work in the next 10 days and completes 35×10 = 350 units of work So far 500 + 450 + 400 + 350 = 1700 units of work is completed and   Remaining work is 2000 - 1700 = 300 units   30 men work in the next 10 days. In each day, they does 30 units of work.   Therefore, additional days required = 300/30 =10   Thus, total 10+10+10+10+10 = 50 days required.

Answer: C) < 85 db Explanation: Sound intensity or level is measured by a unit called a decibel. An 85 decibel noise level is not a safe standard for the public.   Hence, Acceptable noise level for human ear is less than 85 db.

Answer: A) TRUE Explanation: True, Air is a Mixture. Air is considered as mixture for the following reasons ; 1. Air can be separated into its components like N2, O2 , Argon and CO2 by the process of fractional distillation of liquid air. 2. Air shows the properties of all the gases present in the atmosphere. For example : Oxygen is good Supporter of combustion. Hence air also is good supporter of combustion. 3. Air does not have a fixed formula. 4. Air has a variable composition because air at different places contains different amount of gases. 5. Heat or Light energy is neither absorbed nor released when air is prepared physical by mixing required amount of gases . 6. Mixture does have fixed boiling Point. It holds good in case of liquid air.

Answer: B) 2400 Explanation: Given (49.001)2  = ? => =~ 49 x 49 =~ 2401 =~ 2400

Answer: D) All the above Explanation:    1) SO2                  2) CH2Cl2                3) PCl3 How to check the given molecules are polar or non polar : If the electronegativity of the two bonded atoms are different then the bond is polar. Although, some molecules contain polar bonds, the molecule may be non-polar. If the polarity of all the bonds present in the molecule are cancel each other then molecule is non-polar.   In the given options, SO2  is polar because the dipole moments on the O do not cancel. PCl3  is polar because the P-Cl bonds do not cancel out. CH2Cl2  polar because the C-Cl bonds do not cancel.   Hence, in brief, Polar molecules are molecules with net dipole due to the presence of partial positive and partial negative charge. For example, water is a polar molecule that has partial positive and partial negative charge on it. CO2 is a non polar compound.   Therefore, all the given options SO2, CH2Cl2 and PCl3 are Polar molecules.