A) 80 metres
B) 100 metres
C) 140 metres
D) 260 metres
Correct Answer: B
Solution :
The movements of the child from A to E are as shown in fig clearly, the child meets his father at E. Now AF = (AB-FB) = (AB-DC) = (90-30) m = 60m. EF = (DE-DF) = (DE-BC) = (100-20) m = 80m. \[\therefore \] Required distance \[=AE=\sqrt{A{{F}^{2}}+E{{F}^{2}}}=\sqrt{{{\left( 60 \right)}^{2}}+{{\left( 80 \right)}^{2}}}\] \[=\sqrt{3600+6400}=\sqrt{10000}=100m.\]You need to login to perform this action.
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