Equation 1: L+D=(8x60) L+D=480
D=480-L
Equation 2:
D=L+((4x60)+40)
D=L+(280)
480-L=L+280
-280 -280
200-L=L
+L +L
2000=2L
----- ------
2 2
100=L
D=480-L
D=480-100
D=380
it takes L 100 minutes and D 380 minutes
it takes L 1hr 40min and D 6 hr 20 min.