N+2n+20-4=12+3n
3n+20-4-12=12-12+3n
3n+4=3n
3n/3 + 4= 3n/3
n+4=n
n+4-4=n-4
n=n-4
theres no further simplification, unless i messed up ...
8 litres (amount of 20% solution needed) and 7 litres for (amount of 50% solution needed)
<u>Step-by-step explanation:</u>
Let consider ‘x’ for 20% acid solution and (15 – x) for 50% acid solution. And so, the equation would be as below,
20% in x + 50% in (15 – x) = 15 litres of 34%
Convert percentage values, we get
0.20(x) + 0.50 (15 – x) = 15 (0.34)
0.20 x + 7.5 – 0.50 x = 5.1
-0.3 x + 7.5 = 5.1
0.3 x = 7.5 – 5.1
0.3 x = 2.4

Apply ‘x = 8’ value in (15 – x) we get,
15 – 8 = 7 litres
The value of 7 litres for (amount of 50% solution needed)
5 5/16 is greater.
You can find that out by dividing 5/16 and 7/24
So that gives .31 and .29
Thus, 5 5/16 are greater