???? answer please!!!

Question

How many quarts of pure antifreeze must be added tp 3quarts of a 10?% antifreeze solution to obtain a
20?% antifreeze? solution? (Hint: pure antifreeze is? 100% antifreeze.)

 

To obtain a 20?% antifreeze? solution,_____quart(s) of pure antifreeze must be added to
3 quarts of a  10?% antifreeze solution.
?(Round to the nearest tenth as? needed.)

 

 

 

 

Answer 1

Since 100% = 1 and 1p = p...

 

p + .1(3) = .2(3 + p)

p + .3 = .6 + .2p

.8p = .3

p = 3/8 quarts