A) 80 m
B) 100 m
C) 140 m
D) 280 m
E) None of these
Correct Answer: D
Solution :
Explanation Option [d] is correct. The movement of the child from A to E are as shown in figure. Finally the child meets his father at E. Now, \[\operatorname{AF}=\left( 90-30 \right)m=60m.\] \[\operatorname{EF}=\left( DE-DF \right)=\left( DE-BC \right)=\left( 100-20 \right)=80m.\] \[\therefore \] Required distance \[=AE=\sqrt{{{(AE)}^{2}}+{{\left( EF \right)}^{2}}}\]\[=\sqrt{{{(60)}^{2}}+{{\left( 80 \right)}^{2}}}\]\[=\sqrt{3600+6400}\]\[=\sqrt{10,000}=100m.\]You need to login to perform this action.
You will be redirected in
3 sec