On Tuesday, Jeremy read ⁵₇ of a guide book. On Wednesday, he read 15 pages of the guide book. On Thursday, he read ³₇ of the remaining book leaving 68 pages unread.

1. Find the number of pages read on Thursday.
2. Find the total number of pages in the guide book.

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

Number of remaining unread pages after reading on Thursday
= 7 u - 3 u
= 4 u

4 u = 68

1 u = 68 ÷ 4 = 17

Number of pages that Jeremy read on Thursday
= 3 u
= 3 x 17
= 51

(b) 
Working backwards.

Number of pages unread after reading on Wednesday
= 7 u
= 7 x 17
= 119

Total number of pages in the guide book = 7 p

Number of pages unread after reading on Tuesday 
= 7 p - 5 p
= 2 p

2 p = 15 + 119
2 p = 134

1 p = 134 ÷ 2 = 67

Total number of pages in the guide book
= 7 p
= 7 x 67
= 469

Answer(s): (a) 51; (b) 469