What percent is 40 minutes of 1 hour

40/60 = 0.67 (i. e. 2/3) = about 66.67%

1 hour = 60 minutes

60 minutes - 40 minutes = 20 minutes

20 minutes is 1/3 of 60 minutes

1/3 = 33.3%

3/3 (1 hour) - 1/3 (20 minutes) = 2/3 (40 minutes)

2/3 = 33.3% x 2

33.3% x 2 = 66.6%

The answer is 66.6%