The total mass of 3 tanks and 4 boxes was 16.9 kg.
The total mass of 4 tanks and 4 boxes was 18.8 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 = 16.9 --- (1)
4 tanks + 4 boxes = 18.8 --- (2)
(2)
÷ 4 1 tank + 1 box = 4.7 --- (3)
Mass of 1 tank and 1 box = 4.7 kg
(b)
(3) x 3
3 tanks + 3 boxes = 3 x 4.7
3 tanks + 3 boxes = 14.1 --- (4)
(1) - (4)
(3 tanks + 4 tanks) - (3 tanks + 3 tanks) = 16.9 - 14.1
3 tanks - 3 tanks + 4 boxes - 3 boxes = 2.8
1 box = 2.8
6 boxes = 2.8 x 6 = 16.8
Mass of 6 boxes = 16.8 kg
(c)
Substitute 1 box = 2.8 into (3).
1 tank + 1 box = 4.7
1 tank + 2.8 = 4.7
1 tank = 4.7 - 2.8 = 1.9
Mass of 1 tank = 1.9 kg
Mass of 1 tank less than 1 box
= 2.8 - 1.9
= 0.9 kg
Answer(s): (a) 4.7 kg; (b) 16.8 kg; (c) 0.9 kg