On Wednesday, Fred read ⁴₇ of a textbook. On Thursday, he read 12 pages of the textbook. On Friday, he read ²₅ of the remaining book leaving 45 pages unread.

1. Find the number of pages read on Friday.
2. Find the total number of pages in the textbook.

(a)
Number of remaining unread pages after reading on Thursday = 5 u

Number of remaining unread pages after reading on Friday
= 5 u - 2 u
= 3 u

3 u = 45

1 u = 45 ÷ 3 = 15

Number of pages that Fred read on Friday
= 2 u
= 2 x 15
= 30

(b) 
Working backwards.

Number of pages unread after reading on Thursday
= 5 u
= 5 x 15
= 75

Total number of pages in the textbook = 7 p

Number of pages unread after reading on Wednesday 
= 7 p - 4 p
= 3 p

3 p = 12 + 75
3 p = 87

1 p = 87 ÷ 3 = 29

Total number of pages in the textbook
= 7 p
= 7 x 29
= 203

Answer(s): (a) 30; (b) 203