If a number is increased by 37%, by what percent must it be decreased to obtain the original number?

Question

A carpeted living room and dining room area measures 32 ft by 10 ft. Mark decides to install wood flooring in the 12 ft by 10 ft dining room. By what percent has he reduced the area that is carpeted?

Planets A, B, and C orbit a certain star once every 3, 5, and 18 months, respectively. If the three planets are now in the same straight line, what is the smallest number of months that must pass before they line up again?

Rob can complete his bus route in 6 hours. Joan can complete her bus route in 3 hours. If they left the terminal at 3:00 am and after each completed route returned to the terminal, determine the next time they would leavae the terminal at the same time.

Answer 1

Cluless,
If you remain clueless, you will not pass your exam. We like to see you put in some efforts. I will solve the first one for you, and expect you to show some of your work for the rest.
MathMate
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Let the original number be 100.
After increasing by 37%, it becomes
100(1+0.37)=137

To get back to 100, we need to multiply by
137*(100/137)
So the percentage to reduce is
1-100/137=37/137 (convert to %).

Answer 2

The answer would be 27.01%

Answer 3

Hello and thanks for your help. I am not completly dazed. I have 40 questions and these were the ones that I just could not get right. I appreciate efforts and time.

Answer 4

Correct for the 1st one.

For the second, since the width is the same, you can calculate the percentage decrease in the length.

The third one has to do with LCM.

Answer 5

I came up with 90 months for the second one.

The third one would be 9:00 am.

THANKS !