Answer:
24
Step-by-step explanation:
15/2.5=6
multiply 4 by 6 and you get 24.
Find an explicit formula for the geometric sequence −1,−7,−49,−343,...-1\,,-7\,,-49\,,-343,... −1,−7,−49,−343
umka21 [38]
So we see it times 7 each time
starting with -1
geometric
an=a1(r)^(n-1)
a1=first term
r=common ratio
first term is -1
r=7
is the formula
also can look like this:
Using logarithm, the following equation will apply:
Y = P * [1 + z]^x
Where Y = 2000
P = 100
z = 5% = 0.05
x is the quantity we are calculating for
The equation becomes
2000 = 100 * [1+ 0.05]^x
Dividing both side by 100, we have
20 = 10 * [ 1 + 0.05]^x
Taking the log of both sides, we have
Log 20 = Log [1 + 0.05]^x
log 20 = x * log 1.05
x = log 20/ log 1.05 = 61.40
Thus, it will takes 61.40 minutes for the number of cells in the petri dish to reach 2000.
