What is the solution of in story Rikki Tikki Tavi?

The solution to the story "Rikki-Tikki-Tavi" is that Rikki defeats all the snakes that pose a threat to Teddy and his family, successfully protecting his human friends.

Here's a summary of the events leading to the resolution:

1. Rikki gains Teddy's and his parents' trust by saving Teddy from a cobra named Nag, who initially posed the biggest threat.

2. Rikki then engages in a battle with Nag and emerges victorious, marking the first turning point in the story.

3. Later on, Nag's mate Nagaina seeks revenge for her partner's death and poses an even more significant threat as she nearly succeeds in killing Teddy.

4. Rikki intercepts Nagaina's attack, engages her in a tense encounter, and outsmarts her, leading to her eventual defeat.

5. With both Nag and Nagaina defeated, Rikki effectively safeguards Teddy and his family, bringing about a resolution to the central conflict of the story.

Throughout the story, Rikki's resourcefulness, bravery, and determination, along with his bond with the human family, contribute to his successful endeavors against the venomous snakes.