Respuesta :

First convert it into minutes by multiplying 60, 
3/4 * 60

Now, again with 60, in order to convert it into seconds, 
3/4 * 60 * 60
3/4 * 3600
3 * 900
2700

In short, Your Answer would be 2700 seconds

Hope this helps!
3/4 x 3600 sec

= 3 x 900
= 2700 seconds