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Ratios: Which of the following ratios is nearly equal to ...

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by II » Mon Aug 25, 2008 2:32 am
Which of the following ratios is nearly equal to the ratio 1 + √5 to 2 ?

A) 8 to 5
B) 6 to 5
C) 5 to 4
D) 2 to 1
E) 1 to 1

Just interested in finding out other (maybe) quicker approaches.

My approach here was that √5 was between 2 and 3 (since 2^2 =4 and 3^2 = 9). Since 4 is closer to 5, then √5 must must be closer to 2 than 3.
So √5 is approx 2.2
1+2.2 = 3.2

3.2:2 = 3.2 / 2 = 1.6

Go through each answer choice and get a decimal value. A (8/5) is closest to 1.6.

Any other approaches to solve this one ?

Thanks.
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Source: — Problem Solving |

II wrote:Which of the following ratios is nearly equal to the ratio 1 + √5 to 2 ?

A) 8 to 5
B) 6 to 5
C) 5 to 4
D) 2 to 1
E) 1 to 1

Just interested in finding out other (maybe) quicker approaches.

My approach here was that √5 was between 2 and 3 (since 2^2 =4 and 3^2 = 9). Since 4 is closer to 5, then √5 must must be closer to 2 than 3.
So √5 is approx 2.2
1+2.2 = 3.2

3.2:2 = 3.2 / 2 = 1.6

Go through each answer choice and get a decimal value. A (8/5) is closest to 1.6.

Any other approaches to solve this one ?

Thanks.
My approach wud be ..sqrt 5 is 2.23
1+2-2/2 = 1.6
hence A
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sudhir3127 wrote:
II wrote:Which of the following ratios is nearly equal to the ratio 1 + √5 to 2 ?

A) 8 to 5
B) 6 to 5
C) 5 to 4
D) 2 to 1
E) 1 to 1

Just interested in finding out other (maybe) quicker approaches.

My approach here was that √5 was between 2 and 3 (since 2^2 =4 and 3^2 = 9). Since 4 is closer to 5, then √5 must must be closer to 2 than 3.
So √5 is approx 2.2
1+2.2 = 3.2

3.2:2 = 3.2 / 2 = 1.6

Go through each answer choice and get a decimal value. A (8/5) is closest to 1.6.

Any other approaches to solve this one ?

Thanks.
My approach wud be ..sqrt 5 is 2.23
1+2-2/2 = 1.6
hence A
Hi Sudhir,
You approach is no different to mine. Was looking for alternative approaches ... but I guess this is the best way to solve these questions.

Thanks.
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by pepeprepa » Mon Aug 25, 2008 2:58 am
Did the same, except that I compared to the same denominator instead of solving each answer to see which one is closest to 1.6
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II wrote:Which of the following ratios is nearly equal to the ratio 1 + √5 to 2 ?

A) 8 to 5
B) 6 to 5
C) 5 to 4
D) 2 to 1
E) 1 to 1

Just interested in finding out other (maybe) quicker approaches.

My approach here was that √5 was between 2 and 3 (since 2^2 =4 and 3^2 = 9). Since 4 is closer to 5, then √5 must must be closer to 2 than 3.
So √5 is approx 2.2
1+2.2 = 3.2

3.2:2 = 3.2 / 2 = 1.6

Go through each answer choice and get a decimal value. A (8/5) is closest to 1.6.

Any other approaches to solve this one ?

Thanks.
Any approach will need to be pretty similar to the approach you've taken above, though I don't think you really need to work out any decimals here. I would do as follows:

root(5) > root(4) = 2.

So 1 + root(5) > 3, and the ratio in question is greater than 3 to 2. That rules out B, C and E. Since the ratio is clearly less than 2 to 1, there is only one answer choice left- A.
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