Answer:
see the explanation
Step-by-step explanation:
we know that
In an <u><em>Arithmetic Sequence</em></u> the difference between one term and the next is a constant called the common difference
we have
Let
------>
------>
------>
------>
so
the common difference between consecutive terms is equal to 5
we can rewrite the formula as
-----> given formula
For n > 1
where
an is the term that you want to find (position n)
a(n-1) is the known term position (n-1)
Find a_8
For n=8
I need to know a_7
or
we know that
The general formula for arithmetic sequence is equal to
where
an is the term that you want to find (position n)
a_1 is the first term
d is the common difference
n is the number of terms
we have
substitute
so
For n=8
Let the number be x.
3 3/5 of x = 4/5
18/5x = 4/5
x = 4/5 x 5/18
x = 4/18 = 2/9
The number is 2/9
Answer:
28 tiles in 85 minutes
1 tile in 3 minutes
Step-by-step explanation:
Figure out how long it takes Meg to lay one tile - 50 / 15 - 3.33 minutes per tile
This suggests that Jessica should take less than 3.33 mins to lay one tile for the statement to be correct.
If she lays 20 tiles in 85 minutes, it will take her 85 / 20 = 4.25 minutes per tile, so it can't be this one.
If she lays 24 tiles in 85 minutes, it will take her 85 / 24 = 3.5416 minutes per tile, so it can't be this one.
If she lays 28 tiles in 85 minutes, it will take her 85 / 28 = 3.0357 minutes per tile, so it can be this one.
If she lays 1 tile in 3 minutes, it will take her 3 / 1 = 3 minutes per tile, so it can be this one.
If she lays 1 tile in 4 minutes, it will take her 4 / 1 = 4 minutes per tile, so it can't be this one.
:)