1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
VMariaS [17]
3 years ago
11

The number 20,2Δ8 is a 5-digit number with the tens digit covered by a triangle. Given that the number is divisible by 7, what i

s its tens digit? I GIVE BRAINLIEST!
Mathematics
2 answers:
Brrunno [24]3 years ago
8 0

I agree with the other person. <u>The answer is 5.</u>

Here's how we can check to see if a number is divisible by 7.

  • Step 1) Remove the units digit to form a truncated (aka shrunken) number.
  • Step 2) Double the digit we removed.
  • Step 3) Subtract that result from the truncated number.

If the result of the third step is a multiple of 7, then so is the original value itself. We can repeat the steps to progressively shrink the values down so we have something more manageable.

---------------

Let's use those steps to see if 20,258 is a multiple of 7

  • Step 1) Remove the '8' from 20258 to to get 2025
  • Step 2) Double the 8 to get 16
  • Step 3) Subtract 16 from 2025 to get 2025 - 16 = 2009

It's not clear if 2009 is a multiple of 7 or not; however, we can apply the same three steps to shrink the number down. This process can be repeated as many times as you like.

  • Step 1) Remove the 9 from 2009 to get 200
  • Step 2) Double the 9 to get 18
  • Step 3) Subtract to get 200-18 = 182

Like before, the result 182 is fairly big and it's not clear if we have a multiple of 7. Luckily, we only need to do one more round of those steps.

  • Step 1) Remove the 2 from 182 to get 18
  • Step 2) Double that value we removed to get 4
  • Step 3) Subtract to get 18-4 = 14

The result 14 is a multiple of 7, which means that 182 is also multiple of 7. By a domino-like chain reaction, the values 2009 and 20258 are also multiples of 7.

Notes:

  • 182 = 26*7
  • 2009 = 287*7
  • 20258 = 2894*7

---------------

We've just verified that 20258 is a multiple of 7. Let's go over an example a non-multiple of 7. I'll add 1 to the number 20258 so we are guaranteed that it cannot possibly be a multiple of 7. Doing the round of steps as shown above should get us to some smaller non-multiple of 7.

  • Step 1) Remove the 9 from 20259 to get 2025
  • Step 2) Double the 9 to get 18
  • Step 3) Subtract: 2025 - 18 = 2007

Repeat the steps until we get something more manageable

  • Step 1) Remove the 7 from 2007 to get 200
  • Step 2) Double the removed digit: 7*2 = 14
  • Step 3) Subtract: 200-14 = 186

Let's do one more round

  • Step 1) Remove the 6 from 186 to get 18
  • Step 2) Double the digit removed: 2*6 = 12
  • Step 3) Subtract: 18-12 = 6

The value 6 is not a multiple of 7, and neither are 186 and 2007 and 20259.

If you have your calculator with you, then you should see that dividing any of those values over 7 will not lead to a whole number result.

  • 186/7=26.57
  • 2007/7=286.71
  • 20259/7=2894.14

This is a fairly quick and efficient way to check divisibility by 7 if you are in a hurry.

Sati [7]3 years ago
6 0

Answer:

20258. The missing digit is a 5

Step-by-step explanation:

Ok, let's write the number in a more creative way.  That's 21 000 - 700 = 20 300,  minus something else. That something else has to be a multiple of 7, be less than 100, and has to end with a 2. Now start writing down the multiplication table for 7 and find how many of them ends with 2. 42 comes to mind, and that's the only one. (you can go up to 7x14=98 before having one digit too many).

That brings your number to be written as 21000-700 -42 = 20258.

In theory there was a criteria to see if a number was divisible by 7, but I've never learned it.

You might be interested in
Caroline is taking a multiple choice test with a total of 40 points available. Each question is worth exactly 5 points. What wou
Leno4ka [110]

Answer:

30

40 - 5x

Step-by-step explanation:

Caroline is taking test worth 40 points that has 5 points per question.  If she got 2 questions wrong, she would have a score of `30.

2 × 5 = 10

40 - 10 = 30

If Caroline got x questions wrong, she would have a score of 40 - 5x.

5 0
3 years ago
440
Tanya [424]

Answer:

44 degrees

Step-by-step explanation:

if BAC and DAE are complementary then their sum is equal to 90 degrees

90 - 36 = 44 degrees

5 0
3 years ago
Read 2 more answers
24=x^2−4x+3 completing the square
Mars2501 [29]

Answer:

-3,7

Step-by-step explanation:

See the Image below:)

8 0
2 years ago
An online movie streaming plan charges an annual fee of $60 plus $2.50 per
bazaltina [42]

Answer:

1st plan: 24 movies 2nd plan: 10

Step-by-step explanation:

if the 2nd plan has to be the exact value of the 1st plan you would have to divide 6.25 from 62.50.

8 0
3 years ago
Which of the following are based on empirical probability
Vikentia [17]

The empirical probability is Life insurance, Car insurance, and Mortality.

<h3>What is empirical probability?</h3>

The ratio of the number of outcomes in which a defined event occurs to the total number of trials, not in a theoretical sample space but in a real experiment, is the empirical probability, relative frequency, or experimental probability of an event.

Therefore the empirical probability will be Life insurance, Car insurance, and Mortality.

To know more about empirical probability follow

brainly.com/question/16972278

#SPJ1

3 0
2 years ago
Other questions:
  • Plot the points (2, 4) and (2, -8) on the coordinate plane below.
    15·1 answer
  • What is the cirumference of a circle with a diameter of 4.1 cm
    11·1 answer
  • PLEASE! 50 Points!!!!!!
    11·2 answers
  • Help help help help
    5·1 answer
  • Find the number of 3-digit numbers formed using the digits 1 to 9, without repetition, such the numbers either have all digits l
    13·1 answer
  • Leroy owns a business earning $49,300 in profits, these profits are appreciating at about 2.9% each year. What are leroys profit
    10·1 answer
  • 2) university theater sold 556 tickets for a play. tickets cost $22 per adultand $12 per senior citizen. if total receipts were
    11·1 answer
  • 3. A florist sells large floral arrangements for $60 each. Small floral arrangements sell for $15 each. Jenna is buying 2 large
    10·2 answers
  • Ms.Cornick bought 6 new pens for $5.70. How much would it cost her to buy 11 pens at the same rate?​
    12·1 answer
  • Hello answer and I will give you brainliest:No cheating!
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!