Question 420867
Let 82% solution required be x

percent	----------------	quantity
82	----------------	x
water 0%	----------------	20-x
50.00%	----------------	20		
...
82x+0(20	-x)=50*20
82x=1000		
/	82	 							
x=12.2	qt. of82.00%		
Balance 7.8 qt of water.

7.8 qt. of 82% will have to be drained and replaced with water