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Mila [183]
3 years ago
11

Sum to n terms the series 7 +77 +777​

Mathematics
1 answer:
julia-pushkina [17]3 years ago
4 0

Answer:

Step-by-step explanation:

=7 (1+11+111+1111......n)

=7/9 (9+99+999+9999....n)

=7/9 ((10-1)+(10^2-1)+(10^3-1)+....n)

=7/9 ((10+10^2+10^3...n)-(1+1+1+1.....n))

=7/9 ((10 (10^n-1)/(10-1))-n)

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$11,200

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Just multiply the percent times the total

8% * 140000 = .08 * 140000 = 11200

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Todd is saving for a vacation. The cost of his vacation cost $1,089. Todd has a year to save the money. About how much does he n
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He needs to save 90.75

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Answer:

d) $8,100

Step-by-step explanation:

Given information:

  • Money triples every 10 years
  • Initial deposit = $100
  • Number of years invested = 40 years

If the money triples (multiplies by 3) every 10 years,
then in 40 years time it will triple <u>4 times</u>, as 40 ÷ 10 = 4

⇒ Account balance after 40 years = $100 × 3 × 3 × 3 × 3

                                                         = $100 × 3⁴

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<u>Proof</u>

In 10 years time the balance of the account will be:

$100 x 3 = $300

In another 10 years time, the balance of the account will be:

$300 x 3 = $900

In another 10 years time, the balance of the account will be:

$900 x 3 = $2700

In another 10 years time, the balance of the account will be:

$2700 x 3 = $8100

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1 year ago
If you bought a hamburger for $10.25 and a soda for $4.53 and had $9 left over, then how much money did you originally have?
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