So... let's change the concentration percentage to decimal format. .. so 40% is just 4/100 or 0.4 and so on.
so... whatever "x" and "y" may be, we know the must add up to 6 liters.
and whatever 0.4x and 0.8y are, we also know, they must add up to a 3 of concentrated amount.
thus
solve for "x", to see how much of the 40% solution will be needed.
what about "y"? well, y = 6 - x.
You would have to solve for x the plug in the answer for c into the next equation to find your answer
Answer:
see below
Step-by-step explanation:
The equation for half life is
n = no e ^ (-kt)
Where no is the initial amount of a substance , k is the constant of decay and t is the time
no = 9.8
1/2 of that amount is 4.9 so n = 4.9 and t = 100 years
4.9 = 9.8 e^ (-k 100)
Divide each side by 9.8
1/2 = e ^ -100k
Take the natural log of each side
ln(1/2) = ln(e^(-100k))
ln(1/2) = -100k
Divide each side by -100
-ln(.5)/100 = k
Our equation in years is
n = 9.8 e ^ (ln.5)/100 t)
Approximating ln(.5)/100 =-.006931472
n = 9.8 e^(-.006931472 t) when t is in years
Now changing to days
100 years = 100*365 days/year
36500 days
Substituting this in for t
4.9 = 9.8 e^ (-k 36500)
Take the natural log of each side
ln(1/2) = ln(e^(-36500k))
ln(1/2) = -36500k
Divide each side by -100
-ln(.5)/36500 = k
Our equation in years is
n = 9.8 e ^ (ln.5)/36500 d)
Approximating ln(.5)/365=-.00001899
n = 9.8 e^(-.00001899 d) when d is in days
I don’t now good luck!!!!!!!!!!!!!!!!
Answer:
£375
Step-by-step explanation:
Difference will be equal to the difference in VAT
(20% - 17.5%) of 15000
2.5% of 15000
2.5/100 × 15000
375
