The answer is 20.4 you just multiply 1.70 by 12
1w-4= 4-1w
+1w +1w
——————
2w-4=4
+4 +4
—————
2w=8
———
2. 2
w= 4
Let x% be the salt concentration of first solution.
Then in 8ml, amount of salt = 
Given that to this 8ml solution, 11ml solution of a 47% salt solution is mixed.
amount of salt in 11ml of 47% salt solution is
= 
So, total amount of salt in new mixture = 
But given that this new solution is a 43% salt solution.
Hence amount of salt in new mixture of (8+11)=19ml solution of 43% salt solution is 
Hence 
8x+517 = 817
8x=817-517 = 300
x= 300/8 = 37.5
Hence the salt concentration in the first solution is 37.5%
The answer and workings are in the document below. Please open it up in a new window to see it in full.
Answer:
On Monday the value was 1.448, Tuesday it was 1.443, Wednesday it was 1.452, and Thursday it was 1.458.
Step-by-step explanation: