1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
vekshin1
3 years ago
7

We have two varieties of concrete that we can mix together. One is 5% water and 95% concrete mix, and the other is 20% water and

80% concrete mix. We want to end up with 30 pounds of a result that is 10% water and 90% concrete mix. Determine how many pounds of each variety we need.
Mathematics
1 answer:
Orlov [11]3 years ago
5 0

Answers:

  • <u>20 pounds</u> of the 95% concrete mix
  • <u>10 pounds</u> of the 80% concrete mix

=================================================

Explanation:

x = amount of the 95% concrete mix

y = amount of the 80% concrete mix

Type A mix has 95% concrete. If we have x pounds of this, then 0.95x pounds is pure concrete. Type B mix has 80% concrete. If there are y pounds of this, then 0.80y pounds is pure concrete.

So far we have 0.95x+0.80y pounds of pure concrete from the two mixes

Divide this over 30 to get (0.95x+0.80y)/30

Setting this equal to 0.90 means we want the final mix to be 90% concrete.

Since we want 30 pounds total, we can say x+y = 30 which solves to y = 30-x. We'll use this later

-------------------------------

(0.95x+0.80y)/30 = 0.90

0.95x+0.80y = 30*0.90 .... multiply both sides by 30

0.95x+0.80y = 27

0.95x+0.80(30-x) = 27 ..... plug in y = 30-x

0.95x+0.80*30-0.80*x = 27

0.95x+24-0.80x = 27

0.15x+24 = 27

0.15x = 27-24 ..... subtracting 24 from both sides

0.15x = 3

x = 3/0.15 ........... dividing both sides by 0.15

x = 20

y = 30-x

y = 30-20

y = 10

You might be interested in
X2 - 12x+36<br> A) (x-6)(x + 6)<br> B) (x+6)2<br> C) (x-6)<br> D) (x+12)(x – 3).
lys-0071 [83]

Answer:

C) (x-6)^2

Step-by-step explanation:

x2 - 12x+36

What two numbers multiply to 36 and add to -12

-6*-6 = 36

-6+-6 = -12

(x-6) (x-6)

(x-6)^2

7 0
3 years ago
Belinda uses drink mix to make a 2 quart pitcher of lemonade. She has a can of drink mix that makes 3 gallons. How many pitchers
IRINA_888 [86]
1 gal = 4 quarts


3 gal = 4 * 3 = 12 quarts


12 / 2 = 6 pitchers
7 0
3 years ago
If you toss a cube with the numbers 1-6 on it, what is the probability of rolling 7?
garri49 [273]

Answer:

0

Step-by-step explanation:

There is no 7

7 0
3 years ago
Read 2 more answers
What is the slope of the line represented by the equation
marin [14]

Answer:

a). -1/2

Step-by-step explanation:

5 0
3 years ago
Read 2 more answers
Is qrs congruent to tuv if so name the postulate that applies
m_a_m_a [10]
Given triangles Q R S and T U V with segment QS congruant to T V, segment RS is congruent to segment U V and angle Q is congruent to angle T, thus the given congruency suggest A. S S or S S A which is not a complete reason for congruency.

Therefore, the two given triangles might not be congruent.
6 0
3 years ago
Read 2 more answers
Other questions:
  • Identify the population and sample in the following study:
    11·1 answer
  • Gabby, Mary, and Chrisrt were rasing money for their school. Mary got 4 times as much money as Christy. Christy got 2 times as m
    7·2 answers
  • Math problem ^^^ please help
    10·1 answer
  • Explain the difference between buying and leasing and automobile.
    7·1 answer
  • The mean number of daily surgeries at a local hospital is 6.2. Assume that surgeries are random, independent events. (a) The cou
    11·1 answer
  • For brainiest:):):):):):):):)
    9·2 answers
  • Do anyone know this question?
    13·1 answer
  • Solve the simultaneous equation 5x-4y=10. X+2y=9
    13·1 answer
  • Evaluate the expression.
    13·1 answer
  • Dr. Jekyll has 180 mL of solution that is 20% acid. How many mL of
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!