Four friends start from four towns, which are at the four corners of an imaginary rectangle. They meet at a point which falls inside the rectangle, after travelling distances of4O, 50, and 60 metres. The maximum distance that the fourth could have travelled is (approximately):
We need to pair up the distances in a way such that, D's distance is to be maximum.
∴ OC2 + OB2 = OA2 + OD2
602 + 502 = 402 + OD2
( 3600 + 2500) = 1600 + OD2
(6100 - 1600) = OD2
OD = √4500
∴ OD = 67.08
The ans. will be A. 67 metres .