Answer: it will take 9 hours.
Step-by-step explanation:
The rain is falling at the rate of 1.5 inches per hour. This means that the height of water in the barrel is increasing in arithmetic progression.
The formula for determining the nth term of an arithmetic sequence is expressed as
Tn = a + d(n - 1)
Where
a represents the first term of the sequence.
d represents the common difference.
n represents the number of terms in the sequence.
From the information given,
a = 18 inches
d = 1.5 inches
The expression becomes
Tn = 18 + 1.5(n - 1)
For the number of hours it would take to collect 30 inches of rain in the barrel, Tn = 30
Therefore,
30 = 18 + 1.5(n - 1)
1.5(n - 1) = 30 - 18
1.5(n - 1) = 12
n - 1 = 12/1.5 = 8
n = 8 + 1
n = 9
<h3>
Answer: A and B (first answer choice)</h3>
Explanation:
Both figures shown in A and B are triangular pyramids. The base is a triangle, and the lateral sides are also triangles. Another example would be rectangular pyramids where the base is a rectangle, and the lateral sides are triangles.
Choice C is ruled out because cones aren't considered pyramids.
Choice D is a combination of a rectangular prism, and a rectangular pyramid stacked on top, so it's not purely a pyramid only. We can rule out choice D.
Answer:

Step-by-step explanation:
Move the -4 over to the other side.

Divide both sides by 3.

Answer:
<u>x = -3</u>
Step-by-step explanation:
-5x + 9 = 24
move the nine to the other side
-5x = 15
divide
x = -3
U write it as 1/6+1/6+1/6+1/6=4/6