On Wednesday, Archie read ²₅ of a novel. On Thursday, he read 21 pages of the novel. On Friday, he read ⁵₇ of the remaining book leaving 30 pages unread.

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

(a)
Number of remaining unread pages after reading on Thursday = 7 u

Number of remaining unread pages after reading on Friday
= 7 u - 5 u
= 2 u

2 u = 30

1 u = 30 ÷ 2 = 15

Number of pages that Archie read on Friday
= 5 u
= 5 x 15
= 75

(b) 
Working backwards.

Number of pages unread after reading on Thursday
= 7 u
= 7 x 15
= 105

Total number of pages in the novel = 5 p

Number of pages unread after reading on Wednesday 
= 5 p - 2 p
= 3 p

3 p = 21 + 105
3 p = 126

1 p = 126 ÷ 3 = 42

Total number of pages in the novel
= 5 p
= 5 x 42
= 210

Answer(s): (a) 75; (b) 210