A person climbs a hill in a straight path from point ‘O’ on the ground in the direction of north-east and reaches a point ‘A’ after travelling a distance of 5 km. Then, from the point ‘A’ he moves to point ‘B’ in the direction of north-west. Let the distance AB be 12 km. Now, how far is the person away from the starting point ‘O’? (a) 7 km
(b) 13 km
(c) 17 km
(d) 11 km
(b) According to the given information, the direction diagram of a person is as shown below:
Required distance, BO2 = BA2 + OA2 BO2 = 122 + 52 BO2 = 144 + 25 BO2 = 169 BO = 13 km
So, he is 13 km far away from the starting point O.
