Expert: Scott A Wilson - 9/30/2009

Question
Peter is reading a 193-page book. He has read three pages more than one fourth of the number of pages he hasn't yet read.
a)How many pages has he not yet read?
b)Estimate how many days it will take Peter to finish the book if he reads about 8 pages a day.

Answer
He has read N pages.  He has not read 193-N pages.

N - 3 = (193-N)/4, so multiply both sides by 4.  This gives 4N - 12 = 193 - N.

Add N+12 to both sides.  This gives 5N = 205.

From here, it can be seen that N = 41, and that's how many pages he has read.

a) Not read is 193-N, and N=41, so 193-41=152.

b) If he reads 8 pages a day, after 2 days that's 16 pages, 3 days makes 24,
and n days makes 8n.  Setting 8n = 192 gives n = 192/8 = 24.