Puzzles/Arithmetical puzzles/Eggs to Market/Solution

He started with 7 eggs. How?

See Below:

At the market the farmer had 1 egg.

Working backward from toll gate two, the only way that could happen is by giving up half his eggs plus half an egg (dividing 3 into half to get 1.5 plus .5 to give up 2 eggs, leaving 1 egg).

Again working backward from toll gate one, the only way that could happen is by giving up half his eggs plus half an egg (dividing 7 into half to get 3.5 plus .5 to give up 4 eggs, leaving 3 eggs).

So, the farmer left the farm with 7 eggs!