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Sub 505 (Easy)|   Geometry|      
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The lengths of the sides of a triangle are in the ratio of 3 to 5 to 6 17 Aug 2017, 23:31
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E
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The lengths of the sides of a triangle are in the ratio of 3 to 5 to 6. If the perimeter of the triangle is 70, what is the length of the longest side?

(A) 5
(B) 6
(C) 15
(D) 25
(E) 30
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E
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The lengths of the sides of a triangle are in the ratio of 3 to 5 to 6 18 Aug 2017, 00:29
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Let the sides of the triangle are
3k,5k and 6k
Given perimeter(3k+5k+6k) =70
Solving for k, k =5.
So longest side of the triangle is 6k =6*5=30

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The lengths of the sides of a triangle are in the ratio of 3 to 5 to 6 18 Aug 2017, 02:39
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the length of the longest side is = 6/14 * 70 = 30

hence, answer = E
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The lengths of the sides of a triangle are in the ratio of 3 to 5 to 6 03 Dec 2017, 22:55
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Hi All,

We're told that the ratio of the lengths of the sides of a triangle are 3 to 5 to 6 and that the perimeter of the triangle is 70. We're asked for the length of the longest side.

When it comes to ratios questions on the GMAT, you will almost always be dealing with integers (and while there are some exceptions, they're relatively rare). Thus, the first side of this triangle will likely be an integer multiple of 3, the second side an equivalent multiple of 5 and the third side an equivalent multiple of 6. By extension, the SUM of the sides will be a multiple of 14.

For example:
3, 5 and 6 -- Perimeter = 14
6, 10 and 12 -- Perimeter = 28
9, 15 and 18 -- Perimeter = 42
Etc.

Since we know the perimeter = 70 and 70 = (14)(5), we know that each side is 5 times the number in the ratio. In this case, the three sides would be 15, 25 and 30.

Final Answer:
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E


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The lengths of the sides of a triangle are in the ratio of 3 to 5 to 6 05 Jan 2018, 08:08
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Bunuel
The lengths of the sides of a triangle are in the ratio of 3 to 5 to 6. If the perimeter of the triangle is 70, what is the length of the longest side?

(A) 5
(B) 6
(C) 15
(D) 25
(E) 30
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We can let the sides of the triangle = 3x, 5x, and 6x; thus:

3x + 5x + 6x = 70

14x = 70

x = 5

Thus, the longest side is 6(5) = 30.

Answer: E
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