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Question 36562: 1) A square piece of paper is folded in half vertically. If the resulting figure has a perimeter of 12 cm, what was the area of the original square?
2) Find the value of the digit A if the 5-digit number 12A3B is divisible by both 4 and 9, and A=/B (The sign between the A and B is actually an equal sign with a slash going through it, not sure what it means).
3) What is the sum of the digits used to form the integers from 45 to 100, inclusive?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 1) A square piece of paper is folded in half vertically. If the resulting figure has a perimeter of 12 cm, what was the area of the original square?
Let the square have sides of "s" before the folding.
After the folding the sides are s,s,s/2,s/2
The perimeter of the resulting rectangle is 3s=12 cm.
Then s=4 cm
The area of the original square is 4^2 = 16 cm^2
2) Find the value of the digit A if the 5-digit number 12A3B is divisible by both 4 and 9, and A=/B (The sign between the A and B is actually an equal sign with a slash going through it, not sure what it means).
If the number is divisible by "9" the sum of the digits is 9 or 18 or 27
or some numtiple of 9.
If the number is divisible by "4" it must be an even number.
Trying different combinations of digits that meet these criteria you will
find that A=1 and B=2 is a correct answer.
3) What is the sum of the digits used to form the integers from 45 to 100, inclusive?
I assume their is some simple way to do this but I do not know what it is.
Cheers,
Stan H.
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