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Zepler [3.9K]
3 years ago
11

What is the tens digit in the sum 7! + 8! + 9! + … + 2006!

Mathematics
1 answer:
Lena [83]3 years ago
8 0

You can get the tens digit of any number <em>n</em> by computing the quotient

(<em>n</em> (mod 100)) / 10

and ignoring the remainder.

Taking the given sum (mod 100) gives

7! + 8! + … + 2006! ≡ 7! + 8! + 9! (mod 100)

since the last 1997 terms (i.e. 10! up to 2006!) in the sum are multiples of 100. That is,

• every term beyond 100! is obviously a multiple of 100

• every term beyond 25! contains a factor of both 4 and 25

• every term beyond 10! contains two factors each of both 2 and 5 (i.e. every factorial term contains 4, 5, and 10)

The remaining sum is easy to compute by hand:

7! + 8! + 9! = 7! (1 + 8 + 8 × 9) = 5040 × 81 = 408,240

so the tens digit is 4.

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A survey of 600 randomly selected high school students determined that 290 play organized sports. what is the probability that a
blsea [12.9K]

Answer:

29/60

Step-by-step explanation:

probability of playing is 290/600 which when simplified is29/60

5 0
2 years ago
HELLPPPPPPPPPPP PLEASE
KiRa [710]
Alright, so we plug (-2) in for x. (-2)^2 =4, and we can plug that in as 4(4)+(-2)+5. Next, 4*4=16, so we get 15+(-2)+5. After that, we get 15-2+5=18
3 0
3 years ago
Evaluate the expression.<br> 7.4+6 - 12:4<br><br><br> Plz help me
juin [17]

Answer:

7 . 4 + 6 - 12 : 4 = 31

Step-by-step explanation:

* To solve this problem lets revise the order of operations in

  mathematics

- The operations are:

# Addition

# Subtraction

# Multiplication

# Division

# Exponentiation

# Grouping ⇒ Parenthesis or brackets

- The order of these operations is:

# Parenthesis

# Exponents

# Multiplication and Division which comes first from left to right

# Addition and Subtraction which comes first from left to right

- There is a word made from the first letter of each operation

  PEMDAS to remember the order of operations

* Lets solve the problem

∵ 7 . 4 + 6 - 12 : 4

∵ The (.) means multiply the numbers

∵ The symbol (:) means divided the numbers

∴ At first multiply 7 by 4 and divide 12 by 4

∴ (7 × 4) + 6 - (12 ÷ 4)

∴ 28 + 6 - 3

∵ Addition comes before subtraction from the left

∴ (28 + 6) - 3

∴ 34 - 3 = 31

∴ 7 . 4 + 6 - 12 : 4 = 31

4 0
3 years ago
Please help whoever answers this correctly I'll mark your answer brainliest​
Oksana_A [137]

Answers:

  1. Incorrect
  2. Correct
  3. Correct

==================================================

Explanation:

When applying any kind of reflections, the parallel sides will stay parallel. Check out the diagram below for an example of this.

So PQ stays parallel to RS. Also, QR stays parallel to PS.

The statement "PQ is parallel to PS" is incorrect because the two segments intersect at point P. This letter "P" is found in "PQ" and "PS" to show the common point of intersection. Parallel lines never intersect.

4 0
2 years ago
Find the square root of 196 with process.​
blsea [12.9K]

Answer:

The square root of 196 is 14

Step-by-step explanation:

Prime factorization of 196:

  • 2² × 7²

Prime factors of 196 in pairs:

  • (2 × 2) × (7 × 7)

Now square root of 196:

  • √196 = √(2 × 2) × (7 × 7)
  • √196 = √(2 × 7)²
  • √196 = (2 × 7)
  • = 14

Thus, The square root of 196 is 14

<u>-TheUnknownScientist</u><u> 72</u>

3 0
3 years ago
Read 2 more answers
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