The speed at which a man can row a boat in still water is 15 kmph. If he rows downstream, where the speed of current is 3 kmph, what time will he take to cover 90 metres?
Choose the correct choice from the following options:  A) 16 seconds  B) 76 seconds  C) 26 seconds  D) 12 seconds  E) 18 seconds
Speed of the boat downstream = 15 + 3= 
<gadget id="calculator">15 + 3</gadget>
<output>18</output>
18 kmph= 18 * 5/18= 
<gadget id="calculator">18 * 5/18</gadget>
<output>5</output>
5 m/s   Hence time taken to cover 90 m= 90/5= 
<gadget id="calculator">90/5</gadget>
<output>18</output>
18 seconds.   Answer: 18 seconds
<result>E</result>
The speed at which a man can row a boat in still water is 15 kmph. If he rows downstream, where the speed of current is 3 kmph, what time will he take to cover 90 metres?