A) \[30\,\,{{m}^{2}}\]
B) \[40\,\,{{m}^{2}}\]
C) \[40\,\,{{m}^{2}}\]
D) \[60\,\,{{m}^{2}}\]
Correct Answer: D
Solution :
Distance covered by A to cross a field diagonally \[=52\times \frac{15}{60}=13\,m\] And distance covered by B to cross a field along its side \[=68\times \frac{15}{60}=17\,m\] Let l and b be the length and breadth of field. \[\therefore \] \[{{l}^{2}}+{{b}^{2}}=169\] ? (i) and \[l+b=17\] ?(ii) \[\Rightarrow \] \[{{(l+b)}^{2}}=289\] \[\Rightarrow \] \[{{l}^{2}}+{{b}^{2}}+2lb=289\] \[\Rightarrow \] \[169+2lb=289\] \[\Rightarrow \] \[lb=60\] \[\therefore \] Area of field \[=60\,{{m}^{2}}\]
You need to login to perform this action.
You will be redirected in
3 sec
