It's simplify of Indices<br>please help asap, will mark brainliest answer to correct answer

(a) Suppose you have 9 gold coins that look identical, but you also know one (and only one) of them is counterfeit. The counterf

alisha [4.7K]

Answer:

Step-by-step explanation:

You can split the coins into 3 groups, each of them has 3 coins. Weigh group 1 vs group 2, if one is lighter, that group has the fake coin. If both groups weigh the same, then group 3 has the fake coin.

Continue to split the group that has the fake coin into 3 groups, each group has 1 coin. Now apply the same procedure and we can identify the fake coin.

Total of scale usage is 2

b) if you have $3^n$ coins then you can apply the same approach and find the fake coin with just n steps. By splitting up to 3 groups each step, after each step you should be able to narrow down your suspected coin by 3 times.

Step 1: you narrow down to group of $\frac{3^n}{3} = 3^{n-1}$ coins

Step 2: you narrow down to group of $\frac{3^{n-1}}{3} = 3^{n-2}$ coins

Step 3: you narrow down to group of $\frac{3^{n-2}}{3} = 3^{n-3}$ coins

...

Step n: Step 1: you narrow down to group of $3^{n-n} = 3^0 = 1$ coin

8 0

3 years ago

Hii plss helpp quick i have 3 minn

Alexandra [31]

1) 2.625 miles
2) 5.9 miles

8 0

2 years ago

What do the following two equations represent? -3x-y = 3−3x−y=3minus, 3, x, minus, y, equals, 3 -3x-y = 3−3x−y=3

allochka39001 [22]

3 x minus y equals 3

4 0

3 years ago

1. A student took 60 minutes to answer a combination of 20 multiple-choice and extended-response questions. She took 2 minutes t

Darina [25.2K]

Answer:

1) m=15 and r =5

2) 4 and 2 ml

3) x= 0.5 and y = -1

Step-by-step explanation:

given that m multiple choice questions and r extended response questions.

Also given that a) m+r = total no of questions =20 ... i and

2m+6r = total time taken = 60 ... ii

b) Divide second equation by 2, m+3r = 30 ... iii

m+r = 20 ... i

Subtract to get 2r =10 or r =5

m = 20-5 = 15

Verify: m+r = 15+5 =20

and 2m+6r = 30+30 = 60 minutes.

Hence verified

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2) Let a litres of 20% solution and b litres of 50% solution be mixed

a) Then total volume = 6 ml = a+b ... i

Resulting solution = 30% of 6 ml = 1.8 = 0.2a+0.5b ... ii

b) Solve i and ii

b = 6-a: substitute in ii.

0.2a + 3-0.5a = 1.8

Or a = 4 ml and b = 2ml

Verify: Total volume = a+b =6ml and

concentration = 0.2(4)+0.5(2) = 1.8 = 30% of 6 ml.

Thus verified

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3) 2x-3y=4 ...i

2x-5y =6... ii

Because x term has the same coefficient in both the equations, elimination is easier.

i-ii gives 2y =-2 or y =-1

Substitute in i, 2x+3 =4 or x = 0.5

So answer is x = 0.5 and y =1

6 0

3 years ago

Hhheleppppp urgggeenttt

tekilochka [14]

They intercept at (-1,5)

6 0

3 years ago

It's simplify of Indicesplease help asap, will mark brainliest answer to correct answer ​

It's simplify of Indicesplease help asap, will mark brainliest answer to correct answer