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never [62]
3 years ago
5

How many ml of 20 percent acid should be added to pure acid to make 70 ml of 30 percent acid?

Mathematics
1 answer:
Novay_Z [31]3 years ago
8 0

Answer:

61.25%

Step-by-step explanation:

How many ml of 20 percent acid should be added to pure acid

to make 70 ml of 30 percent acid?

:

let x = amt of 20% mixture

then

(70-x) = amt of pure acid

:

0.20x + (70-x) =0 .30(70)

0.20x + 70 - x = 21

= 21 - 70

-0.8x =-49

x = 61.25%

x = +61.25 ml of 20% stuff

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Place values for 249.673
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Hi! 

This question is worded a little funny, but i think in understand what it's asking. Forgive me if i'm wrong. 

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If you were to write the number 12, the 1 would be in the tens place and the 2 would be in the ones place. 

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3 0
3 years ago
People go to a carnival. Children tickets cost $4.50 and adult tickets cost $7.25. If they bought 28 tickets and spent $59, how
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2 years ago
In order for a vaccine to be effective, it should reduce a person's chance of acquiring a disease. Consider a hypothetical vacci
Dmitrij [34]

Answer:

Step-by-step explanation:

Let assume that Suppose the chance of contracting malaria is 10% for those who are not vaccinated ;   (since the value) is not given.

Thus;

If the vaccine has no effect, risk of malaria for vaccine and no vaccine are equal to 0.1

Probability of not getting malaria if vaccinated or no vaccinated = 1 - 0.1 = 0.9

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No Vaccine     200 * 0.1 = 20   200 * 0.9 = 180        300-100 = 200

Total                 20 + 10 = 30       90 + 180 = 270                       300

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Probability of not getting malaria if vaccinated = 1 - 0.05 = 0.95

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Total                 20 + 5 = 25       90 + 180 = 275                         300

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