Puzzle 85 | Chain Link Puzzle

You have five pieces of chain, each consisting of three links. You want to make one long chain of these five pieces. Breaking open a link costs 1 Rs, and welding an open link costs 3 Rs. 

Is it possible to make one long chain of the five pieces, if you have just 15 Rs? 

Solution:

Let us name the chains as  1, 2, 3, 4, 5 each having three links. 

Take chain 1 and break open all three links: 1×3=3 Rs.
Take one open link to connect chain 2 and 3:  3 Rs.
Take another open link to connect chain 3 and 4:  3 Rs
Take third open link to connect chain 4 and 5:  3 Rs.

Now you have one long chain ready in only 12 Rs