Questions

NUMERICAL has 9 positions in which 2, 4, 6, 8 are even positions.

And it contains 5 consonents i.e, N, M, R, C & L. Hence this cannot be done as 5 letters cannot be placed in 4 positions.

Therefore, Can't be determined.

Controlled railroad crossing includes warning signs, red lights and railway gates, whereas absence of all of these warning signs like red lights and gates includes uncontrolled railroad crossings. 

A pure substance can be defined as any single type of material that has not been contaminated by another substance. In chemistry, a pure substance has a definite composition. It can be a compound or an element. A pure substance is considered to be a material that consists of one type of "building block" of matter.

Examples of pure substances include tin, sulfur, diamond, water, pure sugar (sucrose), table salt (sodium chloride) and baking soda (sodium bicarbonate).

Tin, sulfur, and diamond are examples of pure substances which are chemical elements. All elements are pure substances.

Water, sugar, salt and baking soda are pure substances which are chemical compounds. Chemical compounds also are pure substances

rand()  returns a random number

random()  returns a random number in a specified range

srand()  initialise a random number generator with a given seed value

randomize()   initializes a random number generator with a random value based o time.

The correct statement from the given options is

The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.

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. 

Dr. A Keshav Krishna, a scientist at the National Geophysical Research Institute (NGRI), has been selected for 2016 National Geoscience Award by the Ministry of Mines in the field of Geo-environmental studies in applied geosciences.