20. A welfare association collected ₹ 202500 as donation from residents of a colony. If each paid as many rupees as there were residents, find the numbers of residents.
AND
21. The area of a square fields is 5184 m². A rectangular field, whose length is twice of its breadth has its perimeter equal to the perimeter of the square field. Find the area to the rectangular field.
Answers
Answer:
Step-by-step explanation:
20. Let the number of residents be x.
Therefore, According to question x people donated x rupees. So equation formed will be -
x × x = 202500
or, x² = 202500
or, ✓x² = ✓202500
or, x = 450
Answer ) There were 450 residents and each one of them paid 450 rupees for donation.
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21.The area of a square field = 5184m^2
The side of square field =
= side × side = area ( area = 5184m^2)
= area = 2 side
= 5184 = 2side
= 5184 / 2 = side
= side = 2592 ( Is the side of square field)
The perimeter of square field =
= 4×side
= 4× 2592
= 10368 ( ans )
According to the question
perimeter of the square field = perimeter of the rectangular field.
So the perimeter of rectangular field is= 10368m
let the breadth of rectangular field be x.
length = 2x
the perimeter of rectangular field =
= 2 × ( L + B ) = perimeter
= 2× ( 2x + x ) = 10368
= 2 × 3x = 10368
= 3x = 10368/2
= 3x = 5184
= x = 5184 /3
= x = 1728
the breaDHt = x = 1728
the length = 2x
= 2× 1728
=3456
So the length is equal to 1728 and the length is equals to 3456.
Area = length × breadth
= 1728 × 3456
= 5971968 ( ans )
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