An intelligent trader travels from 1 place to another carrying 3 sacks having 30 coconuts each. No sack can hold more than 30 coconuts. On the way
he passes through 30 checkpoints and on each checkpoint he has to give 1
coconut for each sack he is carrying. How many coconuts are left in the
end? *

none

Step-by-step explanation:

the man is carrying 3 sacks

each has 30 coconuts

so at total he has 90 coconuts:  30*3= 90  

he passe through 30 checkpoints

ha has to give 1 coconut for each sack

so he gives 3 coconuts each time: 3*1=3

there are 30 ckeckpoints so : 3*30= 90

he has spent all the coconuts unless he has a trick

He starts with 3 sacks with 30 in each sack.

He has to give 1 coconut per sack away. So at first he gives 3 coconuts away.

The first 10 checkpoints he gives away 30 coconuts, so he is left with 2 sacks.

Now he has to give 2 coconuts away. 30/2 = 15, so the next 15 checkpoints he ends up giving away another full sack, so he is left with 1 full sack of 30 coconuts and he has 5 checkpoints left.

Giving away 1 coconut at those checkpoints, he would have 25 left

people went from manufacturing one object at a time by hand to manufacturing many objects in factories