A
this is a geometric sequence since there exists a common ratio r between the terms
r =
=
=
= 3
B
to obtain the next term in the sequence multiply the previous term by 3
= 3
← recursive rule
C
the n th term of a geometric sequence is
=

where
is the first term in the sequence
= 7 ×
← explicit rule
Answer:
The probability that at most 38 of the 60 relays are from supplier A is P(X≤38)=0.3409.
Step-by-step explanation:
We can model this question with a binomial distribution random variable.
The sample size is n=60.
The probability that the relay come from supplier A is p=2/3 for any relay.
If we use a normal aproximation, we have the mean and standard deviation:

The probability that at most 38 of the 60 relays are from supplier A is P(X≤38)=0.3409:

To find the area of an oblique triangle there are different formulae. The first formula to calculate the area of a triangle is area A = (1/2) * a * b * Sin(C), where a and b are the lengths of the two sides of the triangle and C is the value of the angle of the triangle that lies in between the two sides a, b.
Since line AB is multiplied by 3 to get line XY, you would multiply 2 by 3 to get 6. The answer is J, or 6. Hope this helps!