The total mass of 3 tanks and 4 boxes was 25.8 kg.
The total mass of 6 tanks and 6 boxes was 43.8 kg.
- What is the mass of 1 tank and 1 box?
- What is the mass of 7 boxes?
- How much less is the mass of 1 box than 1 tank?
(a)
3 tanks + 4 boxes = 25.8 --- (1)
6 tanks + 6 boxes = 43.8 --- (2)
(2)
÷ 6 1 tank + 1 box = 7.3 --- (3)
Mass of 1 tank and 1 box = 7.3 kg
(b)
(3) x 3
3 tanks + 3 boxes = 3 x 7.3
3 tanks + 3 boxes = 21.9 --- (4)
(1) - (4)
(3 tanks + 4 tanks) - (3 tanks + 3 tanks) = 25.8 - 21.9
3 tanks - 3 tanks + 4 boxes - 3 boxes = 3.9
1 box = 3.9
7 boxes = 3.9 x 7 = 27.3
Mass of 7 boxes = 27.3 kg
(c)
Substitute 1 box = 3.9 into (3).
1 tank + 1 box = 7.3
1 tank + 3.9 = 7.3
1 tank = 7.3 - 3.9 = 3.4
Mass of 1 tank = 3.4 kg
Mass of 1 tank less than 1 box
= 3.9 - 3.4
= 0.5 kg
Answer(s): (a) 7.3 kg; (b) 27.3 kg; (c) 0.5 kg