7/ 10 square meter is divided into five parts, two of which are 7/ 10 × 2/5 = 7/25.
The second one is not clear
One square meter is divided into seven parts, three of which are a/7 square meters.
third
Read 2/5, and the remaining 3/5 didn't read 60. The book is 60÷ 3/5 = 100 pages.