+0  
 
0
115
1
avatar+414 

A biologist has two brine solutions, one containing 5% salt and another containing 20% salt. How many milliliters of each solution should she mix to obtain 1 L of a solution that contains 14% salt?

5% solution   ___  mL

20% solution    ___ mL

 Dec 9, 2019
 #1
avatar+109064 
+1

First thing  is that there are  1000mL   to each litre

 

So....we have this equation

 

(N ) (.05)  + (1000 - N) (.20)  =   1000(.14)        simplify

 

.05N  +  200 - .20N  =  140

 

-.15N  + 200  = 140    subtract  200 from both sides

 

-.15N  = -60      divide both sides by   -.15

 

N = 400 =  mL  of 5%  solution

 

1000 - N  =  1000 - 400  =   600mL  of 20% solution 

 

 

cool cool cool

 Dec 9, 2019

8 Online Users