Let, snake catches the mouse in t hours. Till then mouse is travelling from
( t + 1.5 ) hours.
Distance, travelled by mouse in t hours is, [tex]d = 100(t+ 1.5)[/tex] .
To catch the mouse snake had to travel the same distance d in t hours.
So,
[tex]200t = 100( t + 1.5 )\\\\2t = t + 1.5\\\\t = 1.5 \ hours[/tex]
Therefore, snake will catch mouse in 1.5 hours.