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. How many pages has he not yet read?

Let x be the number of pages he hasn't read yet.

Peter has read x/4 + 3 pages.
The total number of pages in the book is x + x/4 + 3 = 193.
Multiplying through the parenthesis we get 4x + x +12 = 772
Combining like terms we get 5x+12=772
Subtracting 12 from both sides we get 5x=760
Dividing both sides by 5 we get x= <<152=152>>152. Answer: \boxed{152}.

Let's break down the information given:

Let x represent the number of pages Peter has not yet read.

According to the problem, Peter has read three pages more than one-fourth of the number of pages he hasn't yet read.

This can be written as the equation:

x/4 + 3 = 193 - x

Now let's solve for x:

x/4 + 3 = 193 - x

Multiply both sides of the equation by 4 to eliminate the fraction:

x + 12 = 772 - 4x

Combine like terms:

5x + 12 = 772

Subtract 12 from both sides:

5x = 760

Divide both sides by 5:

x = 152

So, Peter has not yet read 152 pages.