A certain distance is covered at a certain speed. If half of this distance is covered in double the time, the ratio of the two speed is :

Solution (By Examveda Team)

Let the original speed be S₁ and time t₁ and distance be D.
Now,
$$\eqalign{ & \frac{{ {\frac{D}{2}} }}{{2{t_1}}} = {S_2} \cr & {S_2} = \frac{D}{{4{t_1}}}\,{\text{and}}\,{S_1} = \frac{D}{{{t_1}}} \cr & {\text{Thus}}, \cr & \frac{{{S_1}}}{{{S_2}}} = \frac{4}{1} = 4:1 \cr} $$