
Two cars start at the same time from one point and move along two roads at right angles to each other. Their speeds are 36 km/ hour and 48 km/hour respectively. After 15 seconds the distance between them will be

 400 m
 150 m
 300 m
 250 m
Correct Option: D
Let O be the starting point. The car running at 36 kmph is moving along OB and that at 48 kmph moving along OA. Also let they reach at B and A respectively after 15 seconds.
∴ OA = 48 ×  × 15 = 200 m  
18 
∴ and OB = 36 ×  × 15 = 150 m  
18 
∴ Required distance = AB
= √(200)_{2} + (150)_{2}
W (By Pythagoras theorem)
= √40000 + 22500
= √62500
= 250 m