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25 votes
Divide 72 in the ratio 3:4:5​

User Jamlee
by
8.8k points

2 Answers

9 votes

Answer:

18, 24, 30

Explanation:

Here are two methods of solving this problem.

1)

We can do this by trial and error.

The ratio needs to be 3:4:5 with a sum of 72.

Try 3 + 4 + 5 = 12. That is way too small.

Multiply each number by 4:

4 * 3 = 12

4 * 4 = 16

4 * 5 = 20

Now add the products: 12 + 16 + 20 = 56. That is closer.

Try multiplying the numbers in the ratio by 6.

6 * 3 = 18

6 * 4 = 24

6 * 5 = 30

Add the products: 18 + 24 + 30 = 72

That is the answer.

Answer: 18, 24, 30

2)

We can do this with an equation.

We know we need to multiply the three numbers in the ratio by a number, but we don't know what that number is. Let's call the multiplier x.

The numbers in the ratio become

3x

4x

5x

We want their sum to be 72.

3x + 4x + 5x = 72

12x = 72

x = 72/12

x = 6

Now we know the multiplier is 6.

6 * 3 = 18

6 * 4 = 24

6 * 5 = 30

Answer: 18, 24, 30

User Petrichor
by
7.8k points
7 votes

Answer:

72

Total number of parts = 3 + 4 + 5. = 12 parts. Each part = 72 ÷ 12.

User Lazersmoke
by
7.9k points

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