The total mass of 3 tanks and 4 boxes was 22.9 kg.
The total mass of 5 tanks and 5 boxes was 31 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)
3 tanks + 4 boxes = 22.9 --- (1)
5 tanks + 5 boxes = 31 --- (2)
(2)
÷ 5 1 tank + 1 box = 6.2 --- (3)
Mass of 1 tank and 1 box = 6.2 kg
(b)
(3) x 3
3 tanks + 3 boxes = 3 x 6.2
3 tanks + 3 boxes = 18.6 --- (4)
(1) - (4)
(3 tanks + 4 tanks) - (3 tanks + 3 tanks) = 22.9 - 18.6
3 tanks - 3 tanks + 4 boxes - 3 boxes = 4.3
1 box = 4.3
8 boxes = 4.3 x 8 = 34.4
Mass of 8 boxes = 34.4 kg
(c)
Substitute 1 box = 4.3 into (3).
1 tank + 1 box = 6.2
1 tank + 4.3 = 6.2
1 tank = 6.2 - 4.3 = 1.9
Mass of 1 tank = 1.9 kg
Mass of 1 tank less than 1 box
= 4.3 - 1.9
= 2.4 kg
Answer(s): (a) 6.2 kg; (b) 34.4 kg; (c) 2.4 kg