Answer:
Since he hasn't read 70% of the book which is 35 pages, we need to know that 70% of what number is 35.
This is called a is over of, percent over 100 proportion.
If we place 70 over 100 and set that equal 35 over x we can cross multiply and divide to find the answer.
35 times 100 = 3,500
3,500 ÷ 70 = 50
Explanation: