Answer:
B. 13
Step-by-step explanation:
Solve this by setting up system of equations:
0.25x + 0.10y = 3.95
x + y = 20
x equals the number of quarters and y equals the number of dimes. 0.25 is the value of a quarter and 0.10 is the value of a dime.
1. Multiply one equation to have the same coefficient as the other
0.10 · (x + y = 20) = 0.10x + 0.10y = 2
2. Subtract to find the value of one variable
0.25x + 0.10y = 3.95
<u>- 0.10x + 0.10y = 2</u>
0.15x = 1.95
3. Solve for x by dividing both sides by 0.15
x = 13
F=ar^t if the half-life is 96 years...
.5=r^96
ln(.5)=96lnr
ln(.5)/96=lnr
r=e^((ln.5)/96)
f=800e^(336(ln.5)/96)
f=70.71
So about 71mg will remain after 336 years.
<h2>Number of bacteria after 6 days is 2313</h2>
Step-by-step explanation:
Population after n days is given by
Initial population, P₀ = 1000
Increase rate, r = 15 % = 0.15
Number of days, n = 6
Substituting
Number of bacteria after 6 days = 2313