An arithmetic sequence is a sequence with the difference between two consecutive terms constant. The difference is called the common difference. A geometric sequence is a sequence with the ratio between two consecutive terms constant. This ratio is called the common ratio.
Answer:
7.5
Step-by-step explanation:

Answer:
Apprentice = $800
Journeyman = $1600
carpenter = $4000
Step-by-step explanation:
Let the apprentice earns X dollars.
Then ,
Journeyman will make 200% of apprentice's earning which is 2X.
Also,
Carpenter makes 250% of the earning that journeyman makes.
Which is 2.5(2X) = 5X
Their total earning should come to $6400.
Thus,
X + 2X + 5X = 6400
8X = 6400.
X = $800
So,
Earning of apprentice = X = $800
Earning of Journeyman = 2X = $1600
Earning of carpenter = 5X = $4000
Complementary means the two angles add up to 90 degrees. Do 90 - 79 to find the other angle.
It's 11 degrees.