posted by .

John checks every 8th item for color, and Colin checks every 12th item for durability. If 1,920 items passed by both of them, how many items were checked by both John and colin?

How do I figure this?

  • math -

    1920/12 = 160
    1920/8 = 240

    Can you do anything with that?

  • math -

    still confused! do they want to know how many items were checked by BOTH john and calvin, meaning the same item?

  • math -

    John checks items
    #8 #16 #24 #32 #40 .... #1920
    the 8 means he checks item #8 , not 8 items
    so isn't the above just like the times table for 8 ?
    how many entries are there to get to 1920 ?
    that would be 1920/8 or 160
    So John had to check 160 items and that last item would be item # 1920.
    Use the same argument for Colin.

    So John checked 160 items and Colin checked 240 items
    So number of items checked by BOTH John AND Colin = 400

    (I assumed that they were not looking at the same items, if they are checking the same line , then we have to subtract all common items from the total.
    A slightly more difficult question, but ...
    what numbers would be divisible by both 8 and 24 ? )

  • math -

    Its a multible choice question and the choices are 20,40,60,80 and I still don't see how to come up with any of these answers

  • Correction -math -

    You are right, I should have taken the intersection of the two sets, I mis-read the question

    so we are looking for numbers which are both divisible by 8 and by 12
    the smallest of these would be the LCM of 8 and 12 which is 24
    so the 24th is checked by both, the 48th is checked by both, etc
    then 1920/24 = 80

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Math

    There are 5 rows - there are 4 items in each row - there are NO more than 10 items Any idea how this can be solved?
  2. statistics

    2. Punkey Electronics, a small manufacturer of electronic research equipment, has approximately 7,000 items in its inventory. They just hired Joe Detail to manage the inventory. Joe has determined that 10% of the items in inventory …
  3. math

    In a hypermarket promotional drive, the customers would only have to pay half of the original price on their second buy of the same item and one quarter of the original price on their third buy of the same item for some selected items. …
  4. Math

    Market research tells you that if you set the price of an item @ 1.50, you will be able to sell 5000 items; and for every 10 cents you lower the price below 1.50 you will be able to sell another 1000 items. Let x be the # of items …
  5. College algebra

    Assume that the situation described can be modeled by a linear equation. Use the given information to find the y=mx+b form of the equation of the line. Suppose that a sales person observes that if an item is priced at $4 per item then …
  6. statistic

    After packing k boxes (numbered 1,2, ..., k) of m items each, workers discovered that one defective item had slipped in among the km items packed. In an attempt to nd the defective item, they randomly select n items from each box and …
  7. College algebra

    Suppose that a sales person observes that if an item is priced at $3 per item then 11 items are sold. If 9 items are sold for $5 per item then find a liner equation to model the number y of items sold for x dollars per item. Find the …
  8. College Algebra

    A manufacturing company finds that they can sell 375 items at $2.50 per item and 225 items at $3.50 per item. If the relationship between the number of items sold x and the price per item p is a linear one: Find a formula that gives …
  9. Math

    Mrs. Jacobson wants to order toy instruments to give as prizes to her music students. The table shows the prices for various order sizes. Whistles 25 items=$21.25 50 items=$36.00 80 items=$60.00 Kazoos 25 items=$10.0 50 items=$18.50 …
  10. Statistics

    Suppose that the probability that an item produced by a certain machine will be defective is 0.2. A sample of 12 items is chosen. Let X be the number of defectives among the selected 12 items. (a) Find the probability of at most 1 …

More Similar Questions