The total mass of 2 tanks and 3 boxes was 8.7 kg.
The total mass of 6 tanks and 6 boxes was 19.8 kg.
- What is the mass of 1 tank and 1 box?
- What is the mass of 8 boxes?
- How much less is the mass of 1 box than 1 tank?
(a)
2 tanks + 3 boxes = 8.7 --- (1)
6 tanks + 6 boxes = 19.8 --- (2)
(2)
÷ 6 1 tank + 1 box = 3.3 --- (3)
Mass of 1 tank and 1 box = 3.3 kg
(b)
(3) x 2
2 tanks + 2 boxes = 2 x 3.3
2 tanks + 2 boxes = 6.6 --- (4)
(1) - (4)
(2 tanks + 3 tanks) - (2 tanks + 2 tanks) = 8.7 - 6.6
2 tanks - 2 tanks + 3 boxes - 2 boxes = 2.1
1 box = 2.1
8 boxes = 2.1 x 8 = 16.8
Mass of 8 boxes = 16.8 kg
(c)
Substitute 1 box = 2.1 into (3).
1 tank + 1 box = 3.3
1 tank + 2.1 = 3.3
1 tank = 3.3 - 2.1 = 1.2
Mass of 1 tank = 1.2 kg
Mass of 1 tank less than 1 box
= 2.1 - 1.2
= 0.9 kg
Answer(s): (a) 3.3 kg; (b) 16.8 kg; (c) 0.9 kg