Answer: C) 32 years Explanation: Let Shilpa's present age is p years According to question, p = 4(x+4) – 4(x–4) p = 4x+16 – 4x+16 p = 32 Shilpa's present age = 32 years Rajeev is four years older than Shilpa => Shilpa's present age = Rajeev's age 4 years before. => Rajeev's age 4 years before = 32 years.

Answer: A) Acid rain Explanation: Secondary pollutants include ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight.   Whereas Primary pollutant are those pollutants that are directly emitted from their sources, like CO2, CO, SO2 as these gases are directly emitted form burning of fossil fuels.   Acid rain, which is formed when sulfur dioxide or nitrogen oxides react with water, sulfuric acid etc.   Hence, Acidrain is a secondary air pollutant.

Answer: B) 1839 Explanation: The First Anglo-Afghan War also known as Disaster in Afghanistan was fought between British imperial India and The Emirate of Afghanistan from 1839 to 1842. A British-Indian force attacks Ghazni fort during the First Afghan War, 1839.

Answer: A) Uracil Explanation: A nitrogenous base, or nitrogen-containing base, is an organic molecule with a nitrogen atom that has the chemical properties of a base. The main biological function of a nitrogenous base is to bond nucleic acids together. A nitrogenous base owes its basic properties to the lone pair of electrons of a nitrogen atom.   In DNA, four bases have been found. They are 1. Adenine (A), 2. Guanine (G), 3. Cytosine (C) and 4. Thymine (T).   The first three of these bases are found in RNA also but the fourth which is Uracil (U) is absent in it. RNA contains cytosine and uracil as pyrimidine bases while DNA has cytosine and thymine.

Reflection is what which looks back but can't see.

Answer: D) Hockey Explanation:

Answer: A) 1 TB Explanation: 1 TB  >  1 GB  >  1 MB  >  1 KB   1 Tb (Tera Byte) = 1024 GB 1 GB (Giga Byte) = 1024 MB 1 MB (Mega Byte) = 1024 KB 1 KB (Kilo Byte) = 1024 Bytes 1 Byte = 8 Bit   Hence, largest unit of information is TB (Tera Byte) and smallest unit of information is Bit.

Answer: B) Bombay and Thane Explanation: India's first passenger train run took place from Mumbai to Thane for around 34 kms on 16th April in the year 1853.  That train was hauled by three steam locomotives : Sahib, Sindh and Sultan. That train had 14 carriages, carrying around 400 passengers.