<u>ANSWER</u>
The common ratio is -3.
<u>EXPLANATION</u>
In general, the common ratio of a Geometric Sequence is given by:

We can find the common ratio using any two consecutive terms of the geometric sequence by dividing the subsequent term by the previous term.
The given sequence is -2,6,-18,54
Using the first two terms the common ratio is

We could also used the second and third terms to get

and so on and so forth.
Therefore the common ratio is -3.
Step-by-step explanation:
> 2×2a²×2a²
8a⁴
> 36a³×1/4a²
9a³×1/a²
9a
> 2⁶
> 5²m²
Suppose the larger pump alone can empty the tank in L hours, and the smaller pump can finish the job in S hours, then each hour the large pump empties 1/L portion of the tank, and the small pump empties 1/S per hour
Working together for three hours, they empty the whole tank, which is 100% of it, so 3/L+3/S=100%=1
Larger pump can empty the tank in 4 hours less than the smaller one, so L=S-4
replace L: 3/(S-4)+3/S=1
Make the denominator the same to solve for:
3S/[S(S-4)] +3(S-4)/[S(S-4)]=1
(3S+3S-12)/[S(S-4)]=1
(3S+3S-12)=[S(S-4)]
S^2-10s+12=0
use the quadratic formula to solve for S
S is about 8.6
The answer is not whole hour.
Answer: 0.3741
Step-by-step explanation:
Poison probability ;
P(x) = [U(^x) e(^-U)] ÷ x!
Where U = mean
Note: e = exponential symbol
Number of checks that year = 171
Number of days in a year = 365
U = 171/365 = 0.468
Average checks per day = 0.4685
Probability that at least one check was written per day is can be calculated by;
P(not 0) = 1 - P(0)
Therefore,
P(x) = [U(^x) e(^-U)] ÷ x!
P(0) = [ 0.4685^0 * e^-0.4685] ÷ 0!
P(0) = [ 1 * 0.6259] ÷ 1
P(0) = 0.6259
Therefore,
P(not 0) = 1 - 0.6259 = 0.3741
Answer:
502.4 mm^2
Step-by-step explanation:
First find the area of the larger circle, and then that of the smaller one.
Then subtract the latter (2nd) area from the first.
larger circle area smaller circle area
------------------------- ---------------------------
3.14(14 mm)^2 3.14(6 mm)^ 2
This comes out to 3.14[14^2 - 6^2] mm^ 2 = 3.14[196 - 36] mm^2, or
3.14(160 mm^2) = 502.4 mm^2
The area of the metal washer is 502.4 mm^2.