Answer: B) 138 Explanation: The gram formula mass of a compound is nothing but the molar mass. The molar mass of K2CO3 (Potassium Carbonate) is given by Atomic weights of individual elements are   K (Potassium) = 39 g C (Carbon) = 12 g O (Oxygen) = 16 g   Hence, that of K2CO3 = 39(2) + 12 + 16(3) = 78 + 12 + 48 = 138.

Answer: A) Air Explanation: Light travels fastest in Vacuum. The fastest thing in the whole universe is the speed of light in a vacuum like outer space. It is about 2.99 x 108 m/s.

A Temper.

Pace Count is a way to measure to Ground Distance. Pace Count is nothing but regular single natural step of about 30 inches long.

Resistivity : Resistivity is a measure of the resistance to the flow of electrons.  Conductivity : Conductivity is just the inverse of resistivity, σ = 1/ρ, where σ is conductivity and ρ is resistivity.   Example: Think of a pipe and water, the bigger the pipe, the easier water can flow and thus the lower the resistance.

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: A) 1 : 2 Explanation: 6M + 3B = 4(1M + 1B)6M + 3B = 4M + 4B2M = 1B M/B = 1/2

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.