During a two-year period, the water level in a lake decreased by 20 pe

Question

During a two-year period, the water level in a lake decreased by 20 percent by the end of the first year and increased by 10 percent by the end of the second year. If the lake began the period with a water level of w feet, what was the level, in feet, by the end of the period?

A. 1.2w
B. 1.1w
C. 0.9w
D. 0.88w
E. 0.8w

A. 1.2w
B. 1.1w
C. 0.9w
D. 0.88w
E. 0.8w

vaibhav3005 · Answer

Initial level =  w 
After the 1st year, water level reduces by 20%. Hence, the resulting water level would be 0.8 w 
After the 2nd year, the water level increased by 10%. Hence, the resultant water level would be 1.1*0.8 w = 0.88 w 
Hence, Option D should be the correct answer.

generis · Answer

Decrease by 20%   = .80
Increase by 10% =   1.10

(.8)(1.1) = .88

Multiply that product by original value, w ==> .88w

Answer D

JeffTargetTestPrep · Answer

We are given that the lake began at a level of w feet and that the level decreased 20% and then increased 10%. So the ending level is:

w x 0.8 x 1.1 = 0.88w

Answer: D

sashiim20 · Answer

During a two-year period, the water level in a lake decreased by 20 percent by the end of the first year and increased by 10 percent by the end of the second year. If the lake began the period with a water level of w feet, what was the level, in feet, by the end of the period?

A. 1.2w
B. 1.1w
C. 0.9w
D. 0.88w
E. 0.8w

Water level = w
After first year water level decreased by 20% = 80% of w
After second year water level increased by 10% = 110% of 80% of w
Therefore water level by the end of period = \(\frac{110}{100}\) x \(\frac{80}{100}\) x w = \(\frac{88}{100}\) x w = 0.88w
Answer D...

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Abhishek009 · Answer

Let, initial water level be "w"

Water level after 1st year =  80/100*w   = 0.80w 
Water level after 2nd year =  \frac{0.80w*110}{100}   = 0.88w

Thus, level of water in feet after 2nd year is 0.88w

shashankism · Answer

Initial water level = w feet. 
at the end of first year = 0.8 w
at the end of 2nd year = 0.8 x 1.1 w = 0.88 w

Answer D

During a two-year period, the water level in a lake decreased by 20 pe

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During a two-year period, the water level in a lake decreased by 20 pe

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