Question

four boys in the class sent a valentine to different girls daniel didn't send one to annabel but william sent one to either stacy or deborah stacy didn't get a card from john or peter neither john nor peter sent a card to harriet peter would never sent a card to annabel who sent a valentine to annabel

Answer 1

danial sent a valentine to Annabel

Answer 2

Consider in a class there are 8 students, four boys and four girls. The four boys are Daniel, William, John, and Peter. The four girls are Harriet, Stacy, Annabel, and Deborah.  

1. Annabel did not get any card from Daniel and Peter. So either William or John gave a card to her. It is mentioned that William gave a card either to Stacy or Deborah. Then it is concluded that Annabel received card from John.  

2. Peter did not give any card to Annabel and Harriet. He gave the card to Deborah only.  

3. William and John are the two possibilities. If we assume William gave card to Stacy or Deborah, Then it is already concluded that, John gave card to Annabel. So William gave the card to Stacy.  

4. Then the remaining pair is Daniel and Harriet.