## help please ! will mark brainliest Dr. Hamilton took an alloy containing 40% silver and mixed it with an alloy containing

Question

help please ! will mark brainliest

Dr. Hamilton took an alloy containing 40%

silver and mixed it with an alloy containing

60% silver to get an 80-ounce alloy con-

taining 45% silver. How many ounces of

the 40% alloy did he use?

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2021-09-28T06:05:18+00:00
2021-09-28T06:05:18+00:00 2 Answers
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## Answers ( )

Answer: he used 60 ounces of

the 40% alloy.

Step-by-step explanation:

Let x represent the number of ounces of alloy containing 40%

silver that was used.

Let y represent the number of ounces of alloy containing 60%

silver that was used.

The weight of the alloy made is 80 ounces. It means that

x + y = 80

The amount of silver contained in the first alloy is 40/100 × x = 0.4x

The amount of silver contained in the second alloy is 60/100 × x = 0.6x

The amount of silver contained in the mixture is 45/100 × 80 = 36

Therefore,

0.4x + 0.6y = 36- – – – – – – – – – – – -1

Substituting x = 80 – y into equation 1, it becomes

0.4(80 – y) + 0.6y = 36

32 – 0.4y + 0.6y = 36

– 0.4y + 0.6y = 36 – 32

0.2y = 4

y = 4/0.2

y = 20

x = 80 – 20

x = 60

He used about 60% of alloy