Question

15 points!!!!:

Answer 1

60t+20t=150
80t=150
t=150/80=15/8
Note: t is only half the time, the total time is 15/4=3 hours 45 minutes

Answer 2

150=60*x+20*x
150=80x
x=150/80
x=1, 875 hours

then the time is 2*1,875= 3,75 hour