Chores: Added ch10

Chore: added Ch8 - 10

Chore: changed file name

Chore: changed file name

Chore: Uploaded Ch.7

Chores：Completed problem 09-12

Chores: Solved 3 and 7 in CH4 one more time.

Chore: Tried Ch4 problem 7, Need revisit later

Chores: ch4. problem 3-6 completed

Chores: completed Ch4 problem 1-3

Chores: removed the solution for practice

Chores: Completed Ch3 question 5

Chores: Ch3 question 4 completed

Chores: Ch3 question 3 completed

Chores：Chpater 5 Added