The total mass of 3 tanks and 4 boxes was 20.8 kg.
The total mass of 6 tanks and 6 boxes was 34.8 kg.
- What is the mass of 1 tank and 1 box?
- What is the mass of 9 boxes?
- How much less is the mass of 1 box than 1 tank?
(a)
3 tanks + 4 boxes = 20.8 --- (1)
6 tanks + 6 boxes = 34.8 --- (2)
(2)
÷ 6 1 tank + 1 box = 5.8 --- (3)
Mass of 1 tank and 1 box = 5.8 kg
(b)
(3) x 3
3 tanks + 3 boxes = 3 x 5.8
3 tanks + 3 boxes = 17.4 --- (4)
(1) - (4)
(3 tanks + 4 tanks) - (3 tanks + 3 tanks) = 20.8 - 17.4
3 tanks - 3 tanks + 4 boxes - 3 boxes = 3.4
1 box = 3.4
9 boxes = 3.4 x 9 = 30.6
Mass of 9 boxes = 30.6 kg
(c)
Substitute 1 box = 3.4 into (3).
1 tank + 1 box = 5.8
1 tank + 3.4 = 5.8
1 tank = 5.8 - 3.4 = 2.4
Mass of 1 tank = 2.4 kg
Mass of 1 tank less than 1 box
= 3.4 - 2.4
= 1 kg
Answer(s): (a) 5.8 kg; (b) 30.6 kg; (c) 1 kg