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#1 2011-09-24 23:57:07

zee-f
Member
Registered: 2011-05-12
Posts: 1,220

review on word problems

hey i was wondering if the following are done correctly


16. Sheila can wash her car in 15 minutes. It takes Bob twice as long to wash the same car. How long does it take them to wash the car working together?

16-

17. A container is partially filled with 12 liters of whole milk containing 4% butterfat. How much 1% milk must be added to get a mixture that is 2% butterfat? Construct a table, then solve.


1% milk =k

(0.004)*(12)=(0.48) liters of fat

(0.01)*k=[(0.01)]k

12+k

(0.48)+[(0.01)k]

[0.48]+[(0.01)k]=[(0.02)*(12+k)]

0.48+(0.01)k=0.24+(0.02)k

0.24=(0.01)k

k=24 litters of 1% milk must be added to make the mixture a 2% fat solution


One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3

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#2 2011-09-25 00:06:29

Bob
Administrator
Registered: 2010-06-20
Posts: 10,164

Re: review on word problems

hi zee-f,

16 is good.

I'm looking at 17

Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

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#3 2011-09-25 00:07:37

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: review on word problems

16 Correct!

17 Correct!


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#4 2011-09-25 00:16:16

Bob
Administrator
Registered: 2010-06-20
Posts: 10,164

Re: review on word problems

hi zee-f and bobbym,

Beat me to it.  I got that too!

Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

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#5 2011-09-25 00:17:45

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: review on word problems

Hi Bob;

What beat? I just always put correct. It saves time.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#6 2011-09-25 00:23:25

zee-f
Member
Registered: 2011-05-12
Posts: 1,220

Re: review on word problems

beat me to it lol i like that


One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3

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#7 2011-09-25 00:32:20

zee-f
Member
Registered: 2011-05-12
Posts: 1,220

Re: review on word problems

18. An 80-pound grass seed mixture is 30% bluegrass seed. How many pounds of seed containing no bluegrass seed (0%) should be added to the seed mixture for a resulting blend that is 20% bluegrass seed? Construct a table, then solve.


18-0.2x(80+x)

24=16+0.2x

8=0.2x

x=8/.2

x=40

x= amt of no blue grass seed

19. A boat travels 60 km upstream (against the current) in 5 hours. The boat travels the same distance downstream in 3 hours. What is the rate of the boat in still water?

19-the rate of the boat in still water is x

the rate of the current is b

x+b=20mph

x-b=12mph

2x=32

x=16

x+b=20

16+b=20

b=4 rate of current

20. A duck can fly 2400 m in 10 minutes with the wind. Against the wind, it can fly only 2/3 of this distance in 10 minutes. What is the rate of the wind?

20-


One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3

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#8 2011-09-25 00:55:14

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: review on word problems

18 Is correct.
19 Is correct.

20 I am getting 40 meters / min for the speed of the wind.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#9 2011-09-25 01:07:27

zee-f
Member
Registered: 2011-05-12
Posts: 1,220

Re: review on word problems

yup thats what am getting tooo thank you guyyys


One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3

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#10 2011-09-25 01:08:25

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: review on word problems

Hi zee-f;

Glad you are getting it.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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