At first 10 tolls he will give 3 coconuts for each sack from one particular sack (say 3rd sack).
After crossing 10 checkpoints, he will transfer all the coconuts in 2 sacks and get rid of the 3rd sack; so only 2 sacks with 30 coconuts each will be left.
Now for next 15 checkpoints he will give 2 coconuts for each sack, so for these 15 tolls he will give total 30 coconuts.
Now he is left with only 1 sack containing 30 coconuts and 5 toll booths to go.
Now for the remaining 5 tolls left he will give 1 coconut each.
So in all he pays 65 (30 + 30 + 5) coconuts as tolls he starts with 90 coconuts (30 each in 3 bags).
So remaining Coconuts = 90 – 65 = 25
<span>Hence, he will be left with 1 sack containing 25 coconuts.</span>
