8 days to climb out of the well and 3 days to climb from the water

This question was tricky when I was trying to analyze the same and asked for 5 minutes of my time to reorganize my answer. The recruiter was calm enough and actually obliged me to do the same. I figured it out and answered the number of days would be 5 days. I did not get the answer right. He gave me another chance to prove my mettle. But I still did not get the answer right. The recruiter actually explained where I was going wrong and told me the answer. The right answer is 3 days, so, the frog is every day at 1 foot higher than it was the previous day which increases every day. The day when it is at the height of 8 feet it is out of the well as it jumps 2 feet off from that position.