The total mass of 2 tanks and 3 boxes was 19.9 kg.
The total mass of 4 tanks and 4 boxes was 30.8 kg.
- What is the mass of 1 tank and 1 box?
- What is the mass of 5 boxes?
- How much less is the mass of 1 box than 1 tank?
(a)
2 tanks + 3 boxes = 19.9 --- (1)
4 tanks + 4 boxes = 30.8 --- (2)
(2)
÷ 4 1 tank + 1 box = 7.7 --- (3)
Mass of 1 tank and 1 box = 7.7 kg
(b)
(3) x 2
2 tanks + 2 boxes = 2 x 7.7
2 tanks + 2 boxes = 15.4 --- (4)
(1) - (4)
(2 tanks + 3 tanks) - (2 tanks + 2 tanks) = 19.9 - 15.4
2 tanks - 2 tanks + 3 boxes - 2 boxes = 4.5
1 box = 4.5
5 boxes = 4.5 x 5 = 22.5
Mass of 5 boxes = 22.5 kg
(c)
Substitute 1 box = 4.5 into (3).
1 tank + 1 box = 7.7
1 tank + 4.5 = 7.7
1 tank = 7.7 - 4.5 = 3.2
Mass of 1 tank = 3.2 kg
Mass of 1 tank less than 1 box
= 4.5 - 3.2
= 1.3 kg
Answer(s): (a) 7.7 kg; (b) 22.5 kg; (c) 1.3 kg