The total mass of 3 tanks and 4 boxes was 22.8 kg.
The total mass of 4 tanks and 4 boxes was 25.6 kg.
- What is the mass of 1 tank and 1 box?
- What is the mass of 6 boxes?
- How much less is the mass of 1 box than 1 tank?
(a)
3 tanks + 4 boxes = 22.8 --- (1)
4 tanks + 4 boxes = 25.6 --- (2)
(2)
÷ 4 1 tank + 1 box = 6.4 --- (3)
Mass of 1 tank and 1 box = 6.4 kg
(b)
(3) x 3
3 tanks + 3 boxes = 3 x 6.4
3 tanks + 3 boxes = 19.2 --- (4)
(1) - (4)
(3 tanks + 4 tanks) - (3 tanks + 3 tanks) = 22.8 - 19.2
3 tanks - 3 tanks + 4 boxes - 3 boxes = 3.6
1 box = 3.6
6 boxes = 3.6 x 6 = 21.6
Mass of 6 boxes = 21.6 kg
(c)
Substitute 1 box = 3.6 into (3).
1 tank + 1 box = 6.4
1 tank + 3.6 = 6.4
1 tank = 6.4 - 3.6 = 2.8
Mass of 1 tank = 2.8 kg
Mass of 1 tank less than 1 box
= 3.6 - 2.8
= 0.8 kg
Answer(s): (a) 6.4 kg; (b) 21.6 kg; (c) 0.8 kg