This is a geometric sequence with common ratio (r) = 2.
an = ar^(n - 1)
a4 = a(2)^(4 - 1) = a(2)^3 = 8a
8a = 80
a = 80/8 = 10
7th term (a7) = 10(2)^(7 - 1) = 10(2^6) = 10(64) = 640
Answer:
Sister = 15 years old
Brother = 12 years old
Step-by-step explanation:
Right now, if the brother is B years old and the sister is S years old, B = (4/5)S because the ratio from brother to sister is 4:5, so if one unit is X, B = 4X and S = 5X
Three years ago, the brother was B-3 years old and the sister was S-3 years old. Keeping one unit as X, we have
B = 3X
S = 4X
B-3 = (3/4)(S-3)
Therefore, we have a system of equations
B = (4/5)S
B-3 = (3/4)(S-3)
Substitute (4/5)S for B into the second equation to only have one variable
(4/5)S - 3 = (3/4)(S-3)
(4/5)S - 3 = (3/4)S - 9/4
add 3 to both sides and subtract (3/4)S from both sides to isolate the variable and its coefficient
(1/20)S = 3/4
multiply both sides by 20 to isolate the S
S = 15
B = (4/5)S = 12
Answer:
a) 0.01111
b) 0.4679
c) 0.33747
Step-by-step explanation:
We are given the following in the question:
The number of accidents per week can be treated as a Poisson distribution.
Mean number of accidents per week = 4.5

Formula:
a) No accidents occur in one week.
b) 5 or more accidents occur in a week.

c) One accident occurs today.
The mean number of accidents per day is given by

Answer:
NG ( first and last letter of NBG) = WS ( first and last letter of WTS).
BG = TS
G = S
N =W or NG = WS; BG = TS; G = S; N = W.
Step-by-step explanation:
We use the congruence statement to answer these questions. From the way the congruence statement is written, we can see that N = W (they are in the same relative position in the congruence statement). We also see that G and S are in the same relative position, so G = S.
Since N = W and G = S, this means that NG = WS.
From the congruence statement we can also see that B = T (they are in the same relative position). Since G = S, this means that BG = TS.
Answer:
33.33%
Step-by-step explanation:
6 bikini styles and 2 other types
so, total types is 3
so, bikinis is only 1 of the 3, which is 1/3 or 33.33%