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
ANEK [815]
3 years ago
13

A chemist has two alloys, one of which is 15% gold and 20% lead and the other which is 30% gold and 50% lead. How many grams of

each of the two alloys should be used to make an alloy that contains 82.5 g of gold and 113 g of lead?
Mathematics
1 answer:
vlabodo [156]3 years ago
6 0

Answer: 490 grams of the first alloy should be used.

30 grams of the second alloy should be used.

Step-by-step explanation:

Let x represent the weight of the first alloy in grams that should be used.

Let y represent the weight of the second alloy in grams that should be used.

A chemist has two alloys, one of which is 15% gold and 20% lead. This means that the amount of gold and lead in the first alloy is

0.15x and 0.2x

The second alloy contains 30% gold and 50% lead. This means that the amount of gold and lead in the second alloy is

0.3y and 0.5y

If the alloy to be made contains 82.5 g of gold, it means that

0.15x + 0.3y = 82.5 - - - - - - - - - - - -1

The second alloy would also contain 113 g of lead. This means that

0.2x + 0.5y = 113 - - - - - - - - - - - - -2

Multiplying equation 1 by 0.2 and equation 2 by 0.15, it becomes

0.03x + 0.06y = 16.5

0.03x + 0.075y = 16.95

Subtracting, it becomes

- 0.015y = - 0.45

y = - 0.45/- 0.015

y = 30

Substituting y = 30 into equation 1, it becomes

0.15x + 0.3 × 30 = 82.5

0.15x + 9 = 82.5

0.15x = 82.5 - 9 = 73.5

x = 73.5/0.15

x = 490

You might be interested in
Gretchen can buy 17.4 ounces of Brand A toothpaste for $5.22, or she can buy 26.6 ounces of Brand B toothpaste for $6.65. Which
konstantin123 [22]
Price of Brand A toothpaste for 17.4 ounces = <span>$5.22
</span>Price of Brand A toothpaste for 1 ounce = $5.22/17.4 = 0.3
Price of Brand B toothpaste for 26.6 ounces = $6.65
Price of Brand B toothpaste for 1 ounces = $6.65/26.6 = 0.25
So, if we see the price for per ounce of brand A and B, price of Brand B per ounce is less than brand A.
and if we find the difference between the prices of both = 0.3 - 0.25 = 0.05

Thus, the correct answer is "D", <span>Brand B is the better deal, because it costs $0.05 less per ounce than Brand A".</span>
3 0
3 years ago
Read 2 more answers
Shane needs a total of $305 to buy a new bicycle. He has $35 saved. He earns $15 each week delivering newspapers. How many weeks
Tju [1.3M]

Answer:

He will work for 18 weeks.

Step-by-step explanation:

7 0
2 years ago
Read 2 more answers
If PQR ~ UTV, find the value of x.
user100 [1]

The value of x is 15.

Solution:

Given ΔPQR \sim ΔUTV.

<em>If two triangles are similar, then the corresponding parts are congruent.</em>

$\Rightarrow \frac{PR}{UV} =\frac{RQ}{VT}

$\Rightarrow \frac{14}{x + 6} =\frac{8}{x -3}

Do cross multiplication, we get

⇒ 14(x - 3) = 8(x + 6)

⇒ 14x - 42 = 8x + 48

Add 42 on both sides.

⇒ 14x = 8x + 90

Subtract 8x on both sides.

⇒ 6x = 90

Divide by 6 on both sides.

⇒ x = 15

The value of x is 15.

5 0
3 years ago
How to improve your class multiplication skills.
mamaluj [8]

Answer:

PRACTICE.....ONCE THERE WAS A TIME WHEN I'D USED TO FAIL IN MATHS.....BUT NOW I ALWAYS GET 90+ IN MATHS!!!!!

5 0
2 years ago
Question 5(Multiple Choice Worth 3 points) (06.04) Evaluate the expression 7x2y, when x = 5 and y = 3. 210 315 525 728
Natali [406]
Plug in values. 
7x2y = 
7(5)2(3) = 
210 <---------------------Answer
7 0
3 years ago
Read 2 more answers
Other questions:
  • A city’s population, P, is modeled by the function P(x) = 78,500( 1.02 )x where x represents the number of years after the year
    12·1 answer
  • Shiloh can run of a mile in nine minutes. Express her speed as a unit rate, in miles per hour.
    6·2 answers
  • Find the distance between each pair of parallel lines with the given equations y=5x-22 y=5x+4
    5·1 answer
  • In a_____ tax system, the tax rate gets higher as the taxable income gets larger
    14·1 answer
  • You’re given two side lengths of 3 centimeters and 5 centimeters. Which measurement can you use for the length of the third side
    10·1 answer
  • Help me plz can somewon help me
    5·2 answers
  • What is the value of p?
    8·2 answers
  • Brian, Alex &amp; Colin share some money in the ratio 1:9:3.
    8·1 answer
  • HELP!!!!!!!!!!!! TELL ME WHERE THE NUMBERS GO
    8·2 answers
  • Question #2, Help...?
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!