A boy can reach a certain place in 15 hours. If he reduces his speed by 1/30th, he goes 5 km less in that time. Find his speed. Answers:
A) 4 km/hr.
B) 6 km/hr
C) 8 km/hr
D) 10 km/hr
E) None of these
Explanation :   Solution: Let the speed be x km/hr. then,   15x - (15 * 29x/30) = 5   =&gt; 30x-29x = 5*2   =&gt; x =10 km/hr.   Answer : 10 km/hr
<result>D</result>
A boy can reach a certain place in 15 hours. If he reduces his speed by 1/30th, he goes 5 km less in that time. Find his speed.