A rectangular plot has dimensions in the ratio 3:2. If a woman running along the circumference of the plot at a speed of 12 km/hr completes one round in 480 seconds, then the area of the plot (in sq. m) is:
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Answered by
3
Time =480sec =480/60 min=8min.
8min=8/60=0.13hours
distance=speed×time
distance=12×0.13km
=1.56km
=1560m
This is also the perimeter of rectangular plot.
Let the ratio multiplyier of sides is x.
so length=3x and width=2x.
so....
2(3x+2x)=10x=1560
10x=1560
x=156.
The area of plot=length×width
=(3x)(2x)
=6x^2
=6(156^2)
=6×24336
=146026m^2
8min=8/60=0.13hours
distance=speed×time
distance=12×0.13km
=1.56km
=1560m
This is also the perimeter of rectangular plot.
Let the ratio multiplyier of sides is x.
so length=3x and width=2x.
so....
2(3x+2x)=10x=1560
10x=1560
x=156.
The area of plot=length×width
=(3x)(2x)
=6x^2
=6(156^2)
=6×24336
=146026m^2
Answered by
8
L:b = 3:2
circumference(d) = 2 (l+b) = 2(3x+2x)
= 2*5x = 10x
s = d/t
s = 12 * 5/18
= 30/9 m/sec
t = 480 sec
s=d/t
30/9 = 10x /480
30/9 = x/48
x = 30*48 /9
x = 160
l = 3*160 = 480 m
b = 2*160 = 320 m
Area of the plot = l*b = 480*320 = 153600 sq m
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