A copy machine can reduce the size of a new paper by 15%.what will the new dimension be if the original size is 8in.by11in?

Question

Need to now how to get percentage in a 8x11sheet of paper 15%

Answer 1

Since the size (or area) of the paper is being reduced, and the original area is 8*11 = 88 sq in, then the copy will have an area of 88*.85 = 74.8.  In theory, their are an infinite pair of dimensions that will make this work.  However if we assume that the ratio of the two sides remains 8 to 11 and allow x=length and y=width, then we get a system of 2 equations in 2 variables:

 

x*y = 74.8 or x = 74.8/y

x/y = 8/11  substitute the above for x

 

74.8/y² = 8/11  cross multiply

 

8y² = 822.8

y² = 102.85

y = 10.14 (length)

 

10.14*x = 74.8

x = 7.38 (width)