Hi Turksonaaron,
You can use the Percentage Change Formula to determine how much bigger/smaller one number is to another.
Percentage Change = (New - Old)/(Old) = Difference/Original
When comparing two numbers (such as 7 and 6), we can plug them into the above formula if the percentage change is something that you need to know...
So, how much bigger is 7 than 6 (from a percentage change standpoint)? (7 - 6)/6 = 1/6 = 16 2/3%
Thus, from a percentage standpoint, 7 is 1/6 greater than 6; written a different way, 7 is 16 2/3% greater than 6.
GMAT assassins aren't born, they're made,
Rich
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Thanks Rich . I can smile ☺ now[email protected] wrote:Hi Turksonaaron,
You can use the Percentage Change Formula to determine how much bigger/smaller one number is to another.
Percentage Change = (New - Old)/(Old) = Difference/Original
When comparing two numbers (such as 7 and 6), we can plug them into the above formula if the percentage change is something that you need to know...
So, how much bigger is 7 than 6 (from a percentage change standpoint)? (7 - 6)/6 = 1/6 = 16 2/3%
Thus, from a percentage standpoint, 7 is 1/6 greater than 6; written a different way, 7 is 16 2/3% greater than 6.
GMAT assassins aren't born, they're made,
Rich
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Height of tree on day 0 = 4When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of 6th year, the tree was 1/5 taller than it was at the end of 4th year. By how many feet the height of the tree increase each year?
1) 3/10
2) 2/5
3) 1/2
4) 2/3
5) 6/5
Let d = the height increase each year
Height of tree at the end of the 1st year = 4+d
Height of tree at the end of the 2nd year = 4+d+d = 4 + 2d
Height of tree at the end of the 3rd year = 4+d+d+d = 4 + 3d
Height of tree at the end of the 4th year = 4+d+d+d+d = 4 + 4d
Height of tree at the end of the 5th year = 4+d+d+d+d+d = 4 + 5d
Height of tree at the end of the 6th year = 4+d+d+d+d+d+d = 4 + 6d
At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year
In other words, 6th year height = 4th year height + 1/5(4th year height)
Or we can write 4 + 6d = (4 + 4d) + 1/5(4 + 4d)
Simplify: 4 + 6d = 6/5(4 + 4d)
Multiply both sides by 5 to get: 5(4 + 6d) = 6(4 + 4d)
Expand: 20 + 30d = 24 + 24d
Simplify: 6d = 4
d = 4/6 = [spoiler]2/3[/spoiler] = D
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Brent
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When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?
A. 3/10
B. 2/5
C. 1/2
D. 2/3
E. 6/5
When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. Since we know that the growth is by a constant amount, we have a linear growth problem. Thus, we can let x = the yearly growth amount in feet:
Starting height = 4
Height after year one = 4 + x
Height after year two = 4 + 2x
Height after year three = 4 + 3x
Height after year four = 4 + 4x
Height after year five = 4 + 5x
Height after year six = 4 + 6x
We are also given that at the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year. This means the height of the tree at the end of year 6 is 6/5 times as tall as its height at the end of year 4. Thus, we can create the following equation:
(6/5)(4 + 4x) = 4 + 6x
To eliminate the fraction 6/5, we multiply the entire equation by 5:
6(4 + 4x) = 20 + 30x
24 + 24x = 20 + 30x
6x = 4
x = 4/6 = 2/3 feet
Answer: D
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