The rectangle should be divided into 4 big parts, in which each should be further divided in half.
The 4 big parts represent the pound of birdseed he has left, but as he has only 3 of 4 of this part represented by the fraction 3/4, then only 3 of these 4 parts should be colored.
Then, as he needs 3/8, that is the reason why the parts are further divided in half, obtaining 8 small parts. Also, in this case, 3 of the 8 parts will be colored.
Answer: 2 days
