Posted by Linda on Wednesday, January 25, 2012 at 8:28am.
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 - Reiny, Wednesday, January 25, 2012 at 9:36am
1920/12 = 160
1920/8 = 240
Can you do anything with that?
- math - Linda, Wednesday, January 25, 2012 at 9:55am
still confused! do they want to know how many items were checked by BOTH john and calvin, meaning the same item?
- math - Reiny, Wednesday, January 25, 2012 at 10:18am
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 - Linda, Wednesday, January 25, 2012 at 10:48am
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 - Reiny, Wednesday, January 25, 2012 at 12:23pm
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
Answer This Question
More Related Questions
- Math - Market research tells you that if you set the price of an item @ 1.50, ...
- College algebra - Suppose that a sales person observes that if an item is priced...
- College algebra - Assume that the situation described can be modeled by a ...
- Math - There are 5 rows - there are 4 items in each row - there are NO more than...
- math - In a hypermarket promotional drive, the customers would only have to pay ...
- statistics - 2. Punkey Electronics, a small manufacturer of electronic research ...
- statistic - After packing k boxes (numbered 1,2, ..., k) of m items each, ...
- Math Problem (please help) - A small fast-food restaurant invests $4,000 to ...
- Math - Colin's back yard is 720ft.In his estimation, the fallen leaves that ...
- Stats - A production process produces an item. In a recent study, the company ...