Social Darwinism was a prominent intellectual theory that was used to justify European Imperialism in the 19th and early 20th centuries. Social Darwinism held that those made better or worse by industrialization were based on the natural predisposition of the people effected. For those who were made better off, the success of those people demonstrated that they had a well-evolved culture and this expansion would help remove or improve underperforming cultures, which were those "chosen" by the fact that they were performing poorly.   Imperialism may encompass a broad range of meanings, including the foreign occupation of one nation by another; one society's control of the internal politics of another; and, especially, foreign extraction of a less powerful nation's natural resources and/or exploitation of its indigenous human resources.   All in all, according to the Social Darwinist, Imperialism was the natural expansion and success of a well-evolved culture and this expansion would help remove or improve underperforming cultures.

Longitude is the measurement east or west of the prime meridian. Longitude is measured by imaginary lines that run around the Earth vertically (up and down) and meet at the North and South Poles. These lines are known as meridians.

Answer: C) It's a high-pressure zone with sinking air Explanation: The Inter-tropical convergence zone rather has rising air, with common thunderstorms and attendant precipitation and is known by seamen as the doldrums. Inter-tropical convergence zone is where the trade winds collide.   Hence, it is not a high pressure zone with sinking air.

Answer: D) Specific enzymes breakdown proteins into amino acids Explanation: Protein digestion occurs in the stomach and duodenum in which 3 main enzymes:   1. Pepsin secreted by the stomach  2. Trypsin and 3. Chymotrypsin secreted by the pancreas   Break down food proteins into polypeptides that are then broken down by various exopeptidases and dipeptidases into amino acids.

Answer: A) Dn = log 2 (n+1) Explanation: A complete binary tree is a binary tree where all the levels have maximum number of nodes except possibly the last level.   The depth of complete binary tree of n nodes will be Dn=log 2 (n+1) where Dn is the height or depth of the tree and n is the number of nodes.

Answer: B) Proton Explanation: Protons carry a positive electrical charge, electrons carry a negative electrical charge and neutrons carry no electrical charge at all. The protons and neutrons cluster together in the central part of the atom, called the nucleus, and the electrons 'orbit' the nucleus.

Answer: D) Chloroplasts Explanation: Photosynthesis takes place inside plant cells in small things called chloroplasts. Chloroplasts contain a green substance called chlorophyll and this absorbs the light energy needed to make photosynthesis happen.

You will get the answer in the riddle itself, if you read the riddle carefully. The riddle says "A cowboy arrives in town on Friday." So Friday is the name of the horse on which he comes. Hence, the only possibility is he arrives on the horse friday on Tuesday, stays for 3 days and leaves on the same horse on Friday.