A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

mathmath333

  • one year ago

Amartya Banerjee has forgotten the telephone number of his best friend Abhijit Roy. All he remembers is that the number had 8-digits and ended with an odd number and had exactly one nine . How many possible numbers does Amartya have to try to be sure that he gets correct number ?

  • This Question is Closed
  1. mathmath333
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \(\large \color{black}{\begin{align} & \normalsize \text{ Amartya Banerjee has forgotten the telephone number }\hspace{.33em}\\~\\ & \normalsize \text{ of his best friend Abhijit Roy. All he remembers is that }\hspace{.33em}\\~\\ & \normalsize \text{ the number had 8-digits and ended with an odd number }\hspace{.33em}\\~\\ & \normalsize \text{ and had exactly one nine . How many possible numbers}\hspace{.33em}\\~\\ & \normalsize \text{ does Amartya have to try to be sure that he gets}\hspace{.33em}\\~\\ & \normalsize \text{ correct number ?}\hspace{.33em}\\~\\ & a.)\ 104\cdot 9^{5} \hspace{.33em}\\~\\ & b.)\ 113\cdot 9^{5} \hspace{.33em}\\~\\ & c.)\ 300\cdot 9^{5} \hspace{.33em}\\~\\ & d.)\ 764\cdot 9^{5}\cdot 6! \hspace{.33em}\\~\\ \end{align}}\)

  2. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    lets take cases :) case 1- 9 at the end|dw:1443696020352:dw| now 9 at 1st->|dw:1443696142160:dw| now for 9 at 2nd/3rd/4th/5th/6th/7th place-> lets take 9 at 2 |dw:1443696303711:dw|

  3. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i think you can use the number more than once in each cell...

  4. mathmath333
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    u did consider the numbers to be distinct but the telephone numbers can repeat the digits

  5. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    oh naww >.< such a grt mistake X.X

  6. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    but good thought process

  7. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    lol, where did he go

  8. mathmath333
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    do u mean the answer is \(\large \color{black}{\begin{align} & 8\times 9^{6}\times 6+8\times 9^{6}+8\times 9^{7} \hspace{.33em}\\~\\ \end{align}}\)

  9. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    ok so the 1st case wuld be- |dw:1443697084281:dw| 2nd-|dw:1443697152608:dw| 3rd-|dw:1443697267227:dw|

  10. mathmath333
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    is that in options

  11. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    yes ^_^ its c

  12. mathmath333
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    answer is \(\large \color{black}{\begin{align} & 300\times 9^{5}\hspace{.33em}\\~\\ \end{align}}\)

  13. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yep! confirmed too!

  14. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    while correcting it i made 2 mistakes >.< 1st - i forgot that 9 comes only once 2nd-o.o i forgot what the mistake was..

  15. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    all of them with 9's should be 8

  16. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i think

  17. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    why 8?

  18. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    nah whoops, i forgot to count for a second

  19. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    u can fill that place with 9 diff nos :)

  20. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah haha

  21. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    brain fade

  22. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    yea happens >.< silly mistakes are the most annoying things

  23. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    haha, yep good luck @mathmath333 and good work @imqwerty

  24. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    :) thanks btw what is the squirrel in ur pfp showin? its hrt? :D

  25. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    hrt?

  26. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    ❤<-- :)

  27. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    haha i dunno, when i first came on open study, i thought it would be good to have something funny so people laugh

  28. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    nah, its a superman squirell

  29. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    haha

  30. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    XD u wanted to make ppl laugh :D HAHhahah nice thoughts :)

  31. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    haha yep! anyway, time for early bed. catchya

  32. imqwerty
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    c ya ima also leave for class :)

  33. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.