Theory:

     When therefore Mr. Fogg proposed this to the elephant’s owner, he refused point- blank. Mr. Fogg persisted, offering the excessive sum of ten pounds an hour for the loan of the animal to Allahabad. Refused. Twenty pounds? Refused also. Forty pounds? Still refused.
 
     Phileas Fogg, without getting in the least flurried, then proposed to purchase the animal outright, and at first offered a thousand pounds for him. The owner, perhaps thinking he was going to make a great bargain, still refused.
 
     Mr. Fogg offered first twelve hundred, then fifteen hundred, eighteen hundred, two thousand pounds. Passepartout was fairly white with suspense. At two thousand pounds the man yielded.
Explanation:
 
When Mr. Fogg had asked for an elephant hire, the elephant's owner did not accept. He disagreed with giving out his elephant for hire. Still, Mr. Fogg did not give up his decision. He was determined to get the elephant hired and kept increasing the hiring amount from ten to forty. The elephant's owner was unwilling to give his elephant for hire. Phileas Fogg had not worried even a little. He immediately proposed to purchase the animal at that very moment, and he offered a thousand pounds for the elephant. The elephant's owner had not accepted the offer still. It must be that he was expecting a great price, and so he kept refusing Fogg's price proposals.

Firstly, Mr. Fogg told him that he would offer twelve hundred, then fifteen hundred, and then eighteen hundred. At last, he admitted to give two thousand pounds for the elephant. Passepartout was shocked; became fairly white at the announcement of Mr. Fogg. The elephant owner accepted to sell his elephant for two thousand pounds.
 
Meaning of difficult words:
 
S.No
Words
Meaning
1.
Point- blank
In a firm and direct way
2.
Propose
To offer or suggest a plan
3.
Excessive
Much more than reasonable or expected
4.
Flurried
Being nervous, worried or confused
5.
OutrightImmediately or openly
6.
BargainTo argue with someone to make them agree upon the best price
7.
YieldTo agree to do something
Reference:
State Council of Educational Research and Training (2019). Term-3 English Standard-7. A Journey by Train by Jules Verne (pp. 79-85). Published by the Tamil Nadu Textbook and Educational Services Corporation.