Answer:
Amount of 5% solution = 5.7 Litres
Amount of 40% solution = 4.3 Litres
Step-by-step explanation:
First, of all, let x be the amount of 5% solution used
Since, the scientist needs 10 L of solution, then;
Let 10 - x be the amount of 40% solution used
Now, we are told that she needs 10 L of a 20% acid solution.
This means that;
5%x + 40%(10 - x) = 20%(10).
Simplifying this gives;
0.05x + 0.40(10 - x) = 0.20 × 10
Expanding the bracket gives;
0.05x + 4 - 0.4x = 2
0.4x - 0.05x = 4 - 2
0.35x = 2
x = 2/0.35
x ≈ 5.7 litres
Thus, she will need to mix 5.7 liters of the 5% solution.
Since 10 - x be the amount of 40% solution used , then;
the amount of 40% solution = 10 - 5.7 = 4.3 litres
the answer is A nervous wreck
Answer:
9 Quarters
8 Dimes
3 Nickels
Step-by-step explanation:
We let the number of quarters be q
number of dimes be d
and
number of nickels be n
Since quarters are worth 0.25, dimes are worth 0.10 and nickels are worth 0.05 and total worth is 3.20, we can write an equation as:
0.25q + 0.10d + 0.05n = 3.20
Next,
3 times as many quarters as Nickels, we can write:
q = 3n
and
5 more dimes than nickel, we can write:
d = n + 5
Substituting these last 2 equations in the first and solving for n gives us:
0.25q + 0.10d + 0.05n = 3.20
0.25(3n) + 0.10(n+5) + 0.05n = 3.20
0.75n + 0.10n +0.5 + 0.05n = 3.20
0.9n = 2.70
n = 2.70/0.9 = 3
n = 3
We know q = 3n, so
q = 3(3) = 9
Also, we know d = n + 5, which means:
d = 3 + 5 = 8
Thus,
There are:
9 Quarters
8 Dimes
3 Nickels
It’s d cuz it has 14 of them
36 ways! All you have to do is multiple the number of seats by the number of people.
