Friday, October 26, 2018

POTW #8 - Keep On Keeping On

Hi again POTWers! Please review last week's solution below and begin to solve this week's POTW. Don't leave it to the last minute!

POTW #7 Solution:


POTW #8 Question:

25 comments:

  1. Grade 7/8 POTW:
    Info:
    - Gains 10 seconds everyday
    - How many times will it show the correct time from age 12 to 90

    I remember trying to do this last year and getting some large number that didn't make much sense, so I'm hoping that I learned from my mistakes and don't multiply some large number by some other large number. Using common sense, we know that the watch will be correct after 12 hours (because am and pm do not matter here) which is 43200 seconds long. Since the watch gains 10 seconds per day, we can divide 43200 by 10 to get 4320 (approx. 11.8 years) until there is a correct time again. There are 78 years from 12 to 90, so we can take 78 and plug it into this wonderful equation seen below this nice smiley face. c:
    years/(years until correct time)
    78/11.8= approx. 6.6
    And since a watch can't be correct 6.6 times, the answer is 6 times.
    Yay. :))))))))

    RWA-ish:
    - Jeff probably should get a new watch soon because then he'll be late for all his meetings and this watch will render useless.

    ReplyDelete
  2. Wait isn't the watch supposed to be good, not stopped? If it was good I don't think it would be correct every 12 hours(probably a much longer period of time).

    ReplyDelete
    Replies
    1. I assumed this question meant that the watch would gain 10 seconds at the end of the day. So, it would be normal(ish) for the whole day, then when it reaches midnight of the next day, it would gain 10 seconds.

      Delete
    2. aaaaaaaaaaand i over thought the question :T

      Delete
    3. Aaaaaaaand that'd right Oliver, I mean Jamin-Oliver-Jamin

      Delete
  3. GRADE 7/8 POTW
    the solution to this POTW is quite simple. In my opinion, you have to find out how many seconds pass on the watch in 78 years and then divide by the number of seconds in 12 hours.
    10 seconds= 1 day . 365 days x 10=3650= 1 year 3650 x 78= 284700= Number of seconds in 78 years

    Number of Seconds in 12 hours= 60x60x12=43200 seconds in 12 hours

    284700/43200= 6.6 Approx. 6.6 is not an integer so 6 is the answer.

    The clock will show the correct time 6 times from the age of 12 to 90.

    ReplyDelete
  4. Maruti
    Seconds in a day 60 x 60 x 24 = 86400
    Since it gains 10 seconds divide that by 10 and it will take 8640 days to show the correct time.
    There are 28468 days because the 12 and 90 birthdays are excluded.
    Divide 28468 by 8640 equals 3.3 approximately but there is P.M. and A.M. so multiply it by 2 so you get 6.6.
    Since you have to round down because there can't be extra days it will show the correct time 6 times from that time frame.

    ReplyDelete
  5. Done on paper 6 times

    ReplyDelete
  6. Answer is 6 times
    Done on paper

    ReplyDelete
  7. Aliyah Meltz
    90-12=78 years
    Since the watch gains ten seconds per day and there is 365 days per year then 365x10=3650. To find the amount of seconds in 78 years then you multiply 3650x78=284,700

    Now since the watch will obviously be correct every 12 hours than since there are 43,200 seconds in 12 hours then 284,700/43,200=6.6

    Because we must round 6.6 then the watch will show the correct time 6 times from Jeff's age 12-90.

    ReplyDelete
  8. 90-12=78
    10 seconds every day
    10*365.25=3652.5 seconds in a year
    3652.5*78=284,895 seconds in 78 years
    now divide this by the number of seconds in 12 hours (half a day)
    12*60*60=43200
    284,895/43,200
    =it equals about 6 so based on that we can assume that it is only six times because it only hits the exact time 6 times it can't be 6 and 1 half or anything else.

    ReplyDelete
  9. I did it on paper and got 6 times.

    ReplyDelete
    Replies
    1. Great responsibility for continuing to record your answer here and your solution in your notebook.

      Delete
  10. There are 365 days in a year, and we must multiply 10 and 365 to find how many seconds in a year. (3650) Then, we need to multiply by the remaining number of years until he reaches 90.
    Jeff's age= 12 Age required= 90 90-12=78

    3650*78=255500+29200=284700
    Based off what I know about clocks (I'm not an expert), every half day should count because the clock ticks 2 rotations in a day. The seconds in half a day are 12 hours*60*60=43200

    We then divide 284700 by 43200 because that is the total time divided by the time taken for one correct rotation.
    284700/43200 roughly equals 6.5, however, we still round down because half a tick does not count as a tick.

    Therefore, the watch shows the correct time 6 times.
    *le gasp*

    ReplyDelete
  11. also subcomment leap years probably don't do much
    I tried factoring them in but it only added like a miniscule amount to the total

    ReplyDelete
  12. POTW:

    First we need to figure out the amount of seconds in one year, if the watch gains 10 seconds every day: 365 x 10 = 3650.
    He will turn 90 in 78 years, as 90 - 12 = 78
    3650 x 78 = 284700.

    Each day has 12 hours. There are 3600 seconds in every hour: 3600 x 12 = 43, 200

    Now, we divide 284700 by 43, 200 giving us 6.590, rounded to 6.6, rounded to 6.

    The clock will be right 6 times.

    ReplyDelete
  13. Seconds in a day 60 x 60 x 24 = 86400
    The watch gains 10 seconds each day, so you would divide that by 10 (8640) and it will take 8640 days to show the correct time.
    There are 28470 days between the 12th and 90th birthdays
    Divide 28468 by 8640 equals 3.3 approximately.
    Since there is P.M. and A.M. you would have to multiply it by 2 so you get 6.6.
    Since you have to round down because there can't be extra days added, it will show the correct time 6 times from when he is 12.

    ReplyDelete
  14. First find the number of second in a day 60*60*24=86400
    Then you need to find how many days it will take for the watch to show the correct time which would be total seconds divided by 10. 8640 days
    Then find the days in 78 years (90-12) 28468
    Then divide and you get 3.3 for each 12 hours.
    multiply by 2 for 1 day
    6.6
    then go down because you are counting the number of days and you can't have half a day.
    6 times

    ReplyDelete
    Replies
    1. Full sentence answer to the question posed please!

      Delete
  15. The watch would gain 1 hour in 60*6 or 360 days, therefore it will gain 12 hours in 12*360= 4,320 days which is equal to 4,320/365 or around 11.8 years.

    Between the age of 12 and 90 there are 78 years, so 78/11.8=6.6, so it would have shown correct time 6 times by the time he is 90.

    ReplyDelete