1)15 ÷ 60+(15+15) ÷ 60 = 3/4 (hours) =45 (minutes).

3 minutes late

2) suppose that after x hours, the car returns from the examination room and picks up four people on foot, then

5x+60x=2* 15

65x=30

X=6/ 13 (hour)

Then four people in the car go to the examination room, arrive in t hours, and then

15-5 *(6/ 13)= 60 tons.

The solution method is t= 1 1/52 (hours).

So * * * time = 6/13+11/52 = 35/52 (hours) =40 and 5/ 13 (minutes) < 42 minutes.

Therefore, the suggestion made by the team leader is feasible.