Question

Melinda's lights went out. She has 3 pairs of red socks in her drawer, 2 pairs of black socks, and 5 pairs of white socks. What is the minimum number of pairs she must remove from the drawer to ensure that she has a pair of each color? i got 7 but the website im using says the answer is 9. how do you work this problem? i took one from each pair then added up 2,1, and 4.. is this the wrong way to work this problem?

Answer 1

First, i think Melinda needs some new lights. http://www.bulbs.com/Light_Bulbs/results.aspx?cm_mmc=Google-_-NonBrand-_-Bulbs-_-light%20bulbs&adpos=1t2&creative=16392895638&AffID=6
this should help her.

Answer 2

yea tell the people making the TEAS test that one..

Answer 3

jim,
i think the people who made the practice test questions are wrong! lol im using this website http://www.testprepreview.com/modules/mathematics2.htm

Answer 4

Best Case Scenario: You pick 3 socks (one of each color). So first sock may be red, then the next may be black, and the third may be white.

Worst Case Scenario: She picks all 5 white socks first. So she has only picked one color so far. Then she picks all 3 red socks as the next group. So she has picked 8 so far. She's gotten 2 colors, but she needs 3 colors. So she needs to pick one more color to guarantee that she gets all 3 colors


Of course she can pick any number of socks and she *may* get 3 different colors. However, there's no guarantee that she'll pick 3 different colors until you consider the worst case scenario. Once you do, you can be certain that somewhere in those 9 socks will be 3 socks of 3 different colors.

Answer 5

is there some kind of formula to be working for these types of questions?

Answer 6

not really, but you can try all possible scenarios (you may be there a while though...)

Answer 7

that's why I only laid out the best and worst case scenarios

Answer 8

well this test is timed so will that just waste time doing that way?

Answer 9

yes because there are roughly 362 thousand scenarios, but if you can see how I'm getting the best and worst case scenarios, then you'll save a ton of time

Answer 10

best case scenario = smallest amount of socks taken out with 3 diff colors

worst case scenario = largest amount of socks taken out with 3 diff colors

Answer 11

is there a way to plug in the answers from the multiple choice to basically guess n check

Answer 12

that trick is only useful if you have a formula to work with

Answer 13

you don't have a formula here, just concepts really

Answer 14

ok could you reexplain how to find the smallest and biggest amount??

Answer 15

maybe word it differently lol

Answer 16

por favor

Answer 17

please*

Answer 18

ok the best case scenario is where you pick 3 socks and you get 3 different colors (and you know this for sure)

make sense?

Answer 19

basically, the better the scenario, the less you have to work and pull out socks (ie you take less time and energy)

Answer 20

with me so far?

Answer 21

ok so when i read the problem i first think i need to find the best case right? and how do i do that

Answer 22

im still confused on finding the scenarios

Answer 23

you want 3 different colors, so you need to pick 3 socks since they are each one color

Answer 24

the best case is that you do the least amount of work and spend the least amount of time doing it

so that means that picking 3 socks is the best option...ie you're hoping this will happen

but...there's no guarantee that it will happen

Answer 25

it's just one case out of 362,880 cases total...which is a lot i know, but there's good news

you can find the worst case scenario and use that to find the answer

you want 3 different colors, so you want each sock to be different

But what if you pick all 5 white socks, then 3 red socks. You've picked 8 socks but only 2 colors so far, which means you need to pick one more (to get 9 total) to get 3 different colors

This is the worst case scenario because it has you doing the most work

Answer 26

If you take out 8 pairs of socks its still possible not to have a pair of every color (you can have all the white and red, but no black) once you get the 9th pair, no matter how you try to pick them, you will always end up with one of each color.

Answer 27

Note in this problem you are not picking individual socks, but pairs. a pair is one object.

Answer 28

oh true, pairs not singles, but think of these socks as general objects (like blocks or pens)...it doesn't matter what they are, just that they're different colors

Answer 29

mkay still kinda in the clouds with this problem but i have to move to the next problem. thanks for the help

Answer 30

maybe it will help if you do this with some objects that are around you (eg: different colored pens)?

Answer 31

i guess im lost bc there really isnt a formula to plug in numbers

Answer 32

this is just one of those problems where you have to think about it in everyday terms and not use a rigorous formula

Answer 33

Which of the following fractions are correctly placed from the least in value to the greatest in value?

A. 1/4, 17/25, 3/4, 11/16
B. 17/25, 1/4, 11/16, 3/4
C. 1/4, 17/25, 11/16, 3/4
D. 1/4, 17/25, 3/4, 11/16
E. 3/4, 17/25, 11/16, 1/4

for this problem what is the quickest way to find the answer since the test is timed with i think 34 questions

Answer 34

but you can see that the worst case comes from adding up the larger numbers first: 5, then 3, then adding 1

you don't add 5 then 2 or 2 then 3, and so on

Answer 35

can you use a calculator?

Answer 36

no calcs

Answer 37

ok you'll have to get each fraction to have a common denominator

Answer 38

we have the denominators: 4, 16, 25

they all need to be the same in order to compare the fractions

Answer 39

that just seems so timeful lol

Answer 40

hmm let me think of a shortcut

Answer 41

you agree that 1/4 is less than 3/4 right?

Answer 42

yes

Answer 43

so that allows you to rule out choice E

Answer 44

ok i see

Answer 45

25 is close to 24, so a quarter of this is 24/4 = 6

so 6/25 is close to 1/4 (not exactly 1/4, but close enough)

this means that 11/25 must be bigger than 1/4 since 11 is bigger than 6

Answer 46

oh i meant 17/25, not 11/25

Answer 47

so there's no way choice B is true, which means we can eliminate that too

Answer 48

so that leaves A, C, and D

btw, choices A and D are identical

is that a typo?

Answer 49

must be but thats how they have it

Answer 50

so the only thing left to compare is 3/4 and 11/16 to see which is bigger

Answer 51

if you multiply top and bottom of 3/4 by 4 to get 12/16

so this shows that 3/4 is bigger than 11/16 (since 12/16 > 11/16)

Answer 52

so that eliminates A and D (which strangely are the same)

leaving C as the only answer

Answer 53

oh i just messaged u

Answer 54

im on to another problem haha

Answer 55

ill post it so i can give u credit for ur hard work

Answer 56

alright lol

Answer 57

no its fine, i don't really care about the medals to be honest