Y=5(0.25)^x is it exponetial decay

Yes

Step-by-step explanation:

Since the exponent is in front of the DECIMAL instead of the five, it is exponential decay because decimals with exponents make the numbers smaller and smaller

This is exponential growth...

f=ir^t, f=final amount, i=initial amount, r=rate, t=time 

f=2r^t so we have a point at ten minutes that says:

8=2r^10

4=r^10

r=4^(1/10) so our equation is:

f=2(4^(1/10)^t)

f=2(4^(t/10))  now we wish to solve for t when f=16

16=2(4^(t/10))

8=4^(t/10)  taking the natural log of both sides...

ln8=(t/10)ln4

t/10=ln8/ln4

t=10(ln8/ln4)

t=15

So after fifteen minutes there will be 16 cells in the bottle...

10:05+:15=10:20

So at 10:20 there will be 16 cells in the bottle.