Answer:
When you have a common denominator of 6, 2 goes to a 4 and 5/6 is greater than 4/6. That is why 5/6 is greater than 2/3.
At age 6, he read six. That doubled would be 12 books. So at age 7, he read 12. 12 doubled is 24. At age 8, he read 24. That doubled would be 48. At age 9, he read 48. That double would be 96. So by age 10, he would have read 96 books.
