TS ICET 23 May 2019 Shift 1 Paper

Let the original speed of the person be 3S kmph.
The distance travelled in 6 hours $=\left(3\mathit{S}\right)\times 6=18$ S km
The distance travelled in 6 hours with reduced speed $=\left(2\mathit{S}\right)\times 6=12$ S km.
Given $18\mathit{S}\mathit{–}12\mathit{S}=10$km
$\Rightarrow 6\mathit{S}=10$
The required answer $3\mathit{S}=5$ kmph