Respuesta :

There are 60 seconds in one minute

3 1/2 minutes =  3 1/2 * 60 = 210 seconds ,   Answer
1 minute= 60 seconds

3 minutes= 60 x 3
               = 180 seconds
1/2 a minute is = 60/2
                         = 30 seconds
Total= 180 seconds + 30 seconds
       =210 seconds