1. ordered pairs

list the order pairs in the relation R from A={0,1,2,3,4} to B={0,1,2,3},where (a,b)belongs to R if and only if
a)a|b
i dont understand how to find these ordered pairs when divide relation occur like a|b and also explain me how to find these ordered pairs

2. Re: ordered pairs

Do you know what "ordered pairs" are? Do you understand that there are only a total of 5(4)= 20 ordered pairs? That those are
(0, 0), (0, 1), (0, 2), (0, 3),
(1, 0), (1, 1), (1, 2), (1, 3),
(2, 0), (2, 1), (2, 2), (2, 3),
(3, 0), (3, 1), (3, 2), (3, 3),
(4, 0), (4, 1), (4, 2), (4, 3) ?

Now, in which of those does the first number evenly divide the second?

3. Re: ordered pairs

i still understand the meaning of order pair but i still dont understand the evenly division
the answer in the book is following
(1,0),(1,1),(1,3),(2,0),(2,2)(3,3)(3,0)(4,0)
but i still dont understand how we get it by a|b

4. Re: ordered pairs

Okay, are you saying that you do not know what "a|b" means? I told you before that you were looking for pairs, (a, b), such that "the first number evenly divides the second".
(2, 2) is in the set because 2 divides into 2 once with no remainder- or, equivalently, 2= 1*2. (2, 3) is NOT in the set because 2 does NOT evenly divide 3. 2 divides into 3 with remainder 1- or equivalently, 3= 2*1+ 1.

5. Re: ordered pairs

ok i understand ,but the order(1,3)and (4,2) have remainder 0 when evenly divide so why dont they are in the set

6. Re: ordered pairs

1 evenly divides 3 so (1, 3) is in the set (every pair (a, b) with a= 1 is in the set). 4 does NOT evenly divide 2: 4 divides into 2 0 times with remainder 2.