The opening fragment can be best followed by fragment Q, as the subject ‘Bigger economies’ will be followed by a verb ‘grow’. This eliminates option B and C. Now since option R makes a better conclusion than fragment P, option A is the most suitable option as the logical order is QPR.

Hence, option A is the correct answer.

• Sentence P should be the first one as it continues to talk about the information given in S1.
  
  
• Q should be the next sentence as it talks about the grandparents of the subject and takes the passage further.
  
  
• Sentence R should be the next one as it mentioned the brothers of the subject.
  
  
• At last comes sentence S. 
  
  
• Thus, the correct sequence is PQRS.
  
  

• R will be the first in the sequence as it introduces us to the topic - Qutub Minar and the person who started its construction.
  
  
• S will be the next in the sequence as it tells who completed the construction. 
  
  
• P will be the next as it tells who did the further modifications.
  
  
• Q will be the last in the sequence.
  
  Thus, the correct sequence will be: RSPQ
  

The opening fragment can be best followed by fragment P, as ‘of utmost importance for’ is a relevant phrase. Also fragment R is the most suitable conclusion, this makes the logical order as PQR given in option D

Hence, option D is the correct answer.

• Only Q can come first in the sequence as it is an independent statement.
  
  
• The use of "for instance" in P suggests that it should come after Q.
  
  
• P talks about “radiotherapy treatment” and S explains it further, so PS is a pair.
  
  
• R is unrelated to the other three sentences as it talks about the third stage so it should come either at the start or at the end.
  
  
• Only option D fulfills all the conditions. 

• The first sentence should be S as it introduces the subject i.e. Sundar Pichai.

• The sentences R and Q form a mandatory pair because they tell about his job responsibilities.

• The sentence P should be the fourth sentence as it tells about Sundar Pichai’s job profile before joining Google.

• Thus, the correct sequence is: SRQP.

After rearranging the sentences, the passage will be: Sundar Pichai joined Google in 2004 and became CEO in August of 2015. Prior to that, he led the product management and innovation efforts for a suite of Google's consumer products, including Google Toolbar, Chrome and Chrome OS. He was also responsible for the HTML5 and open web platform efforts at Google. Before joining Google, he held various engineering and product management positions at Applied Materials.

Hence, option A is the correct answer.

• R defines the term “generation gap” and that is the theme of the sequence so it should come at the starting of the sequence.
• S explains the term "generation gap". Thus, it will be next in the sequence.
  
  
• P states the fact that how generation gap is helpful whereas Q states a contrary statement which has “however” at the beginning.
  
  
• It means PQ is a pair. Only option A fulfills all these conditions.

The opening fragment can be best followed by fragment Q, as the noun “homogeneity” needs a verb after it which is given in Q and P. Hence, the logical order is QPR given in option B.

Hence, option B is the correct answer.

• Sentence Q should be kept at first since it’s the continuation of sentence S1.

• After that P should be put next as it talks about the origin of the word "Raven".

• S should come after that since it talks about sentence P in a more detailed manner.

• R becomes the last sentence.

• Thus, the correct sequence after rearrangement is QPSR.

The opening fragment and fragment Q are mandatory pairs as ‘that’ plays the role of connector after the opening fragment. This eliminates options B and D.

Fragment R is a better conclusion than fragment P, this eliminates option A.

The correct order is QPR

Hence, option C is the correct answer.