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By what percent will a fraction increase if its numerator is decreased by 10% and its denominator is decreased by 50%?

 Feb 21, 2016

Best Answer 

 #2
avatar+23252 
+5

Call the fraction  x/y.

To increase x by 10% :  x + 10%x  =  x + 0.10x  =  1.00x + 0.10x  =  1.10x.

To decrease y by 50%:  y - 50%y  =  y - 0.50y  =  1.00y - 0.50y  =  0.50y.

The new fraction is now  (1.10x) / (0.50y)  =  (1.10/0.50)(x/y)  =  (1.1/.5)(x/y  =  (11/5)(x/y).

11/5  =  2.2   --->   The new fraction is now  2.2 times the old fraction (x/y).

So the new fraction is 2.2 times as large as the old fraction.

2.2 times is 220%; however, to calculate the percentage of increase, you must subtract the original (which is 100%) from this 220% (which represents the original plus the increase); giving an increase of 120%. 

 Feb 21, 2016
 #1
avatar
+5

100/100=90/50=1.9 -1=.80 X 100=80% increase in the fraction

 Feb 21, 2016
 #2
avatar+23252 
+5
Best Answer

Call the fraction  x/y.

To increase x by 10% :  x + 10%x  =  x + 0.10x  =  1.00x + 0.10x  =  1.10x.

To decrease y by 50%:  y - 50%y  =  y - 0.50y  =  1.00y - 0.50y  =  0.50y.

The new fraction is now  (1.10x) / (0.50y)  =  (1.10/0.50)(x/y)  =  (1.1/.5)(x/y  =  (11/5)(x/y).

11/5  =  2.2   --->   The new fraction is now  2.2 times the old fraction (x/y).

So the new fraction is 2.2 times as large as the old fraction.

2.2 times is 220%; however, to calculate the percentage of increase, you must subtract the original (which is 100%) from this 220% (which represents the original plus the increase); giving an increase of 120%. 

geno3141 Feb 21, 2016
 #3
avatar
0

geno3141: BOTH NUMERATOR AND DENOMINATOR ARE DECREASES!!!!

 Feb 21, 2016
 #4
avatar+129849 
0

Call the old fraction, a/b

 

If the numerator decreases by 10%  it is now = .90a

If the denominator decreases by 50% it is now = .50b

 

So

 

.90a / .50b   =

 

9a / [ 5b]  =

 

(9/5) (a/b)

 

So....the fraction increases by 80%

 

 

Guest - it is true that both decrease, but the numerator decreases by less than the denominator.......thus........the fraction actually increases....!!!

 

 

 

cool cool cool

 Feb 22, 2016
 #5
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0

thx

 Feb 22, 2016

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