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sladkih [1.3K]
3 years ago
10

A contractor requires a cement mix that is 70% sand and 30% cement. He has 1400 kg of a cement mix that is 80% sand and 20% ceme

nt. How much cement should he add to this 1400 kg cement mix so that he gets the required mix?
Mathematics
1 answer:
aleksandr82 [10.1K]3 years ago
8 0

Answer:

added cement = 200 kg

Step-by-step explanation:

Sand = 0.8*1400

Sand = 1120 kg

If 1120 kg of sand represents the total sand in the 8:2 mixture.

We have to create the equation of the 7:3 mixture as follows.

The sand amount continues the same but the total amount of the mixture and cement will change.

0.7*mixture_mass + 0.3*mixture_mass = mixture_mass

By replacing values, we have:

1120 kg + 0.3*(1400 kg + added cement)= 1400 kg + added cement

added cement = 200kg

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abruzzese [7]

Now box is 3/4 full


3/4 = 3/4*1


3/4 = 3/4 * 3/3 = 9/12


Box is 9/12 full after heba ate 1/12 of a box of cereal


Initial fraction will be 9/12+1/12


=10/12= 5/6

7 0
3 years ago
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Neil has 3 partially full cans of white paint.They contain 1/3 gallon,1/5 gallon,and 1/2 gallon of paint.About how much paint do
Wittaler [7]

Answer:

  less than 1 1/2 gallons

Step-by-step explanation:

1/3 + 1/6 = 1/2, so the sum of the three cans is more than 1 by the difference between 1/5 and 1/6. That difference is 1/30 gallon. The sum is 1 1/30 gallons, which is less than 1 1/2 gallons.

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A suitable common denominator is 2·3·5 = 30. Then the sum of the fractions is ...

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In decimal, 1/3 ≈ 0.333, 1/5 = 0.200, 1/2 = 0.500, so the sum is ...

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4 0
3 years ago
A+B share a ratio of 2:3 A pays 126 how much does B pay
Alenkasestr [34]
A:B = 2:3

A=126
B=?

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PLEASE ANSWER ASAP!!! FULL ANSWERS ONLY!!!!!! WILL GIVE BRAINLIEST!!!!!!!!!
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Answer:

4r + 4(r + 3) = 68

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distance = rate * time

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