Vijay and Gaurav participated in a bullock cart race. For the first hour, their speed was the same. After that, Vijay increased his speed by 5% every hour. Gaurav increased his speed by 1% in the first hour, by 3% in the next hour, by 5% in the next hour, by 7% in the next hour and so on. At what time will Gaurav overtake Vijay?

1) After 2 hours & 40 minutes
2) After 3 hours 20 minutes
3) After 4 hours & 10 minutes
4) None of these