Questions

Optical illusion is what that refers to persistence of vision with a principle that multiple images blend into a single image in human mind and what is showed in cinema.

Hence, Persistence of vision is the principle behind cinema.

The missing number in the given number puzzle is "78".

Here the logic is the numbers are from 86 - 91 when we read upside down.

India’s space agency on Feb 15th, 2017 launched a record 104 satellites from a single rocket as it crossed another milestone in its low-cost space-exploration program. The satellites from seven countries were carried by the Indian Space Research Organization’s Polar Satellite Launch Vehicle on its 38th consecutive successful flight. On board was a 714kg satellite for earth observation and more than 100 smaller satellites weighing less than 10kg each. Three were Indian-owned, 96 were from US companies, and the rest belonged to companies based in Israel, Kazakhstan, the Netherlands, Switzerland and the United Arab Emirates. Most were owned by Planet Labs Inc, a US-based Earth-imaging company. 

Veins seen in the leaves, serve the function of Transpiration.

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. 

The fall of the Czar is known as February Revolution because, according to the old Russian calender, it occured on 27 February 1917.

Prices do not reflect the full social cost of production is an example of Market failure.

A market failure occurs when the supply of a good or service is insufficient to meet demand. This results in an inefficient distribution of resources among market participants.

It also occurs if externalities are not accounted for.

If a firm fails to maximize its profits this is not a general market failure.