Tactics Practice - Pinning 13-15

I've stated previously that I had some growing concerns about some of the problems I've been posting because the book was printed in 1955.  So, I'm now checking their solutions with my computer before posting them.  Problem 13 and 14 will look really similar today.  The reason is because it is the same starting position.  The first appearance follows the solution as given in the book.  It is a slightly weaker response by black than what my computer discovered, but I think a likely response from a human player. The second appearance of the problem is the variation that the computer found that offers a slightly better response from black.  

Again with the computer solution.

The actual problem 14 from the book I've been forced to skip because of how much the computer disagreed.  I couldn't resolve what I saw at all.  Problem fifteen is as follows:

Good luck with the tactics training everyone.  Hope following along with these helps you ever grow your tactical eyesight.