390 seconds
210 seconds
30 minutes × 60 seconds = 1800 seconds in half an hour.
3.5 minutes is 210 seconds.
2 + 2.5 = 4.5 minutes = 270 seconds
150 seconds.
150 seconds
390 seconds
210 seconds
30 minutes × 60 seconds = 1800 seconds in half an hour.
60 seconds an 1 minute 60 minutes in 1 hour 30 minutes in half an hour 90 minutes in one and a half hours. So 90 minutes * 60 seconds = 5400 seconds
3.5 minutes is 210 seconds.
Half an hour is 1800 seconds. 3 half hours are 5,400 seconds.
2 + 2.5 = 4.5 minutes = 270 seconds
510
330
30.