In a weight-lifting competition, the first weight-lifter lifted a mass of 500 kg 20 g while the second weight-lifter lifted 90 kg 200 g more. Given that the third weight-lifter lifted 70 kg 900 g more than the second weight-lifter, what is the total mass that the 3 of them lifted? (Give the answer in kg and g.)
1 kg = 1000 g

500 kg 20 g = 500 x 1000 + 20 = 500020 g
90 kg 200 g = 90 x 1000 + 200 = 90200 g
70 kg 900 g = 70 x 1000 + 900 = 70900 g

Mass that the first lifter lifted = 500020 g

Mass that the second weight-lifter lifted
= 500020 + 90200
= 590220 g

Mass that the third weight-lifter lifted
= 590220 + 70900
= 661120 g

Total mass that the 3 of them lifted
= 500020 + 590220 + 661120
= 1751360 g
= 1751 kg 360 g

Answer(s): 1751 kg 360 g