The ratio of the length to the width of a rectangle is 3 : 2. If the length of this rectangle is increased by 25% and its width is kept constant, then the area of the rectangle increases by 24 $$m^{2}$$. What is the width of this rectangle?
The ratio of the length to the width of a rectangle is 3 : 2.
Let's assume the length and width of a rectangle is 3y and 2y respectively.
Initially area =Â length $$\times$$ width
=Â $$3y\times2y$$
=Â $$6y^2$$
If the length of this rectangle is increased by 25% and its width is kept constant, then the area of the rectangle increases by 24 $$m^{2}$$.
New length = 3y of (100+25)%
= 3y of 125%
= 3.75y
Initially area + 24Â =Â new area
$$6y^2 + 24 =Â 3.75y\times2y$$
$$6y^2 + 24 = 7.5y^2$$
$$7.5y^2 -Â 6y^2 = 24$$
$$1.5y^2 = 24$$
$$y^2 = 16$$
y = 4
Width of this rectangle = 2y
= $$2\times4$$
= 8 m
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