20% of wood is damaged and thrown away and only 20 kilograms is left vv is its original weight​

The original weight is 4.

Explanation:

20%= 1/5 if u don’t know the percentage then u can simply by doing..

20/100 then u divide it. U can do this by any other numbers such as 2, 4,5,10 and 20. U can do which ever way u like but i would recommend doing it either by 10 or 20.

So if we divide it by 20 we do...

20/100 divided by 20= 1/5

Or

20/100 divided by 10= 2/10

2/10 divided by 2 = 1/5

You can see the bigger the number that fits in is faster, although u can do it any way u feel like doing.

So we have got 1/5 from 20%. Now we do...

1/5 divided by 20. So when we do this, we use the bottom number to divide it and the top number to times it.

So..

1/5 u could use as 20 divided by 5..
Then 1 times the number that u get from ur before sum.

The answer is 4.

Because 1/5= 20 divided by 5 = 4
Since we have a 1 left we do..

4 times 1 which is... 4.

( u don’t need to show these parts in doing ur working, but i am doing these so they can help u understand)

So the answer is 4 and is the original weight.

I hope this is clear and helps u! :D