You first convert everything to minutes
3hrs= 60x3=180mins
1hr= 60x1=60mins
then you add 20 to 180
200
and you also add 48 to 60
104
200-104=
96
Then you convert to hrs and mins
96-60=36
1hr 36mins
Pour 4 times of 124-gallon into a big jug.
Amount of water = 124 x 4 = 496 gallons
Then use the 45-gallon jug to scoop out the water 11 times.
Amount of water scooped out = 11 x 45 = 455 gallons
Water remaining = 496 - 450 = 1 gallon.