Question

Really am stuck on conversions :'(

Answer 1

You wash dishes for a chemistry laboratory to make extra money for laundry. You earn 12 dollars/hour, and each shift lasts 75 minutes. Your laundry requires 12 quarters/load.

Answer 2

@Vocaloid

Answer 3

hm. is this the full question?

Answer 4

How many shifts must you work if you wish to wash 10 loads of laundry?

Answer 5

oh wow this question is worded really weird lemme think...

Answer 6

OKay so would I start with 12 dollars / hour = 12 quarters per load

Answer 7

:S. If you could justexplain in depth once you know. I am having alot of trouble with conversions

Answer 8

well often times we start w/ the quantity we want to know about (so the 10 loads)

Answer 9

the problem tells us that 12 quarters = 1 load so let's add that conversion factor

Answer 10

OKay so we would cancel out the "loads" and get 10 x 12 = 120

Answer 11

right?

Answer 12

yup, that's how many quarters it would take to wash 10 loads

then from there, since 4 quarters = 1 dollar we can add that conversion factor

Answer 13

that puts us in dollars, getting there

12 dollars/hour lets us convert between dollars and time, so:

Answer 14

finally, we go from time to # of shifts with this statement

each shift lasts 75 minutes

as a short-cut, we know that 75 minutes = 1.25 hours so we can write the conversion factor as 1 shift = 1.25 hours

Answer 15

okay , so we can add in our own conversions like ones that are not included in the question too?

Answer 16

just to make it relate

Answer 17

yes

generally it would only be common knowledge stuff like "4 quarters in a dollar" or "60 seconds in a minute"

Answer 18

okay cool and then cross out common units.. for the units that are crossed out, do I stil use that value to multiply into the total

Answer 19

yes

Answer 20

or do i just multiply the numerator first or denominator first, little confused :S

Answer 21

the way I have it set up, the numbers in the top all multiply together to get the numerator

and the numbers at the bottom all multiply together to get the denominator

Answer 22

so 10 * 12 / (4 * 12 * 1.25) should give you your shift #

Answer 23

okay yeaah thats what i needed to hear, i wsnt sure

Answer 24

I got 2

Answer 25

yeah that's what I got too

Answer 26

How many loads of laundry can you wash if you work 3 shifts?

Answer 27

Can i try this on my own and then you check?

Answer 28

I just want to try to get the concept

Answer 29

sure

Answer 30

15?

Answer 31

yeah that's what I got too

Answer 32

How many loads of laundry will each shift pay for if the cost per load rises to 16 quarters?

Answer 33

Ill try to figure this one too

Answer 34

15.75?

Answer 35

hm. I think I got something a little different (accidentally erased my calculations but I can re-do them)

Answer 36

1 shift = 1.25 hours

3 shifts = 3 * 1.25 hours

3 * 1.25 hours * 12 dollars per hour

3 * 1.25 hours * 12 dollars per hour * 4 quarters

then divide by 16

Answer 37

yeah I end up w/ 11.25 (which rounds down to 11)

Answer 38

wait

Answer 39

it's only asking about 1 shift (no idea where I got three from)

Answer 40

so it's just 1.25 hours * 12 dollars per hour * 4 quarters

then divide by 16

Answer 41

OH i got it right.

Answer 42

ONly part I screwed up on is the 12

Answer 43

oh haha I see where your mistake is

the price changed from 12 quarters to 16 quarters per load so the 12 isn't relevant anymore

Answer 44

so in my conversion i have 1 load/12 quarters. that is incorrect?

Answer 45

yeah

the original price was 12 quarters but the new problem changes the price to 16 quarters/load so the 12 quarters/load conversion isn't applicable anymore

Answer 46

so i would just replace the 12 with 16 or wold it alter the entire conversion

Answer 47

also I think there may be a logical error in your approach

if you try and convert 16 quarters to shifts, you're actually asking how many shifts it would take to earn 16 quarters, not how many loads can be washed w/ 1 shift

Answer 48

hard to explain why but that's why I start w/ 1 shift and convert to loads

Answer 49

okay and the final answer is 3.75?

Answer 50

ah

since we are talking about loads of laundry we would round down (if you don't have enough money to finish a load you can't wash anything so round down to the nearest whole #)

Answer 51

so 3