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)
Answer:
Step-by-step explanation:
we know that
The simple interest formula is equal to
where
A is the Final Investment Value
P is the Principal amount of money to be invested
r is the rate of interest
t is Number of Time Periods
step 1
Find the rate of interest
in this problem we have
substitute in the formula above and solve for r
The rate of interest is 
step 2
Find the sum of money that will amount to 25,500 in 5 years, at the same rate of interest
in this part we have
substitute in the formula above and solve for P
Answer:
$7
Step-by-step explanation:
70 / 10 = 7