Sandy had 211 dollars to spend on 9 books. After buying them she had 13 dollars. How much did each book cost ?
1 answer:
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Answer:
Step-by-step explanation:
In order to write the series using the summation notation, first we need to find the nth term of the sequence formed. The sequence generated by the series is an arithmetic sequence as shown;
4, 8, 12, 16, 20...80
The nth term of an arithmetic sequence is expressed as Tn = a +(n-1)d
a is the first term = 4
d is the common difference = 21-8 = 8-4 = 4
n is the number of terms
On substituting, Tn = 4+(n-1)4
Tn = 4+4n-4
Tn = 4n
The nth term of the series is 4n.
Since the last term is 80, L = 4n
80 = 4n
n = 80/4
n = 20
This shows that the total number of terms in the sequence is 20
According to the series given 4 + 8 + 12 + 16 + 20+ . . . + 80 , we are to take the sum of the first 20terms of the sequence. Using summation notation;
4 + 8 + 12 + 16 + 20+ . . . + 80 =
Answer:
\simeq 14.94 billion dollars
Step-by-step explanation:
During the period 1994 - 2004, the 'National Income' ,(NI) of Australia grew about 5.2% per year (measured in 2003 U. S, dollars). In 1994 , the NI of Australia was $ 4 billion.
Now,
(2020 - 1994) = 26
Assuming this rate of growth continues, the NI of Australia in the year 2020 (in billion dollars) will be,
=
=\simeq 14.94 billion dollars (answer)