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A rectangular farm house has a 1km diffe...

A rectangular farm house has a `1km` difference between its sides. Two farmers simultaneously leave one of the vertex of the rectangle for a point at the opposite vertex. One farmer crosses the farmhouse along its diagonal and other walks along the edge. The speed of each farmer is `4km//hr`. If one of them arrives half an hour earlier then the other then the size of farmhouse is .

A

`12kmxx13km`

B

`4kmxx5km`

C

`3kmxx4km`

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
C

According to given condition
`(d+1+d)/(4)=sqrt((d+1)^(2)+d^(2))/(4)=(1)/(2)`
`rArr2d1=sqrt((d^(2)+(d+1)))gtd=3km`
`rArr` size of farm house `3kmxx4km`
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