Question Details

A rectangle becomes a square when its length and breadth are reduced by 10 m and 5 m, respectively. During this process, the rectangle loses 650 m2 of area. What is the area of the original rectangle in square meters?

Options

A

1125

B

2250

C

2924

D

4500

Correct Answer :

2250

Solution :

The correct option is 2250.

Let us denote the length of the original rectangle as l and its breadth as b.
The area of the original rectangle, A, is given by the formula:
A=l×b

According to the first condition, when the length is reduced by 10 m and the breadth by 5 m, the rectangle becomes a square. Since a square has equal sides, the new length and the new breadth must be equal:
l-10=b-5
Rearranging this equation, we get:
l-b=5l=b+5 (Equation 1)

According to the second condition, during this reduction, the area of the rectangle decreases by 650 m2. The new area is:
(l-10)(b-5)=lb-650

Let us expand the left side of the equation:
lb-5l-10b+50=lb-650
Subtracting lb from both sides, we get:
-5l-10b+50=-650
Rearranging the terms:
5l+10b=700
Dividing the entire equation by 5 to simplify:
l+2b=140 (Equation 2)

Now, substitute the value of l from Equation 1 (l=b+5) into Equation 2:
(b+5)+2b=140
Combine the terms containing b:
3b+5=140
Subtract 5 from both sides:
3b=135
Divide by 3:
b=45 m

Now, find the length l using Equation 1:
l=45+5=50 m

Finally, we calculate the area of the original rectangle:
A=l×b=50×45=2250 m2

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