The total mass of 4 tanks and 5 boxes was 18.8 kg.
The total mass of 5 tanks and 5 boxes was 20 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)
4 tanks + 5 boxes = 18.8 --- (1)
5 tanks + 5 boxes = 20 --- (2)
(2)
÷ 5 1 tank + 1 box = 4 --- (3)
Mass of 1 tank and 1 box = 4 kg
(b)
(3) x 4
4 tanks + 4 boxes = 4 x 4
4 tanks + 4 boxes = 16 --- (4)
(1) - (4)
(4 tanks + 5 tanks) - (4 tanks + 4 tanks) = 18.8 - 16
4 tanks - 4 tanks + 5 boxes - 4 boxes = 2.8
1 box = 2.8
8 boxes = 2.8 x 8 = 22.4
Mass of 8 boxes = 22.4 kg
(c)
Substitute 1 box = 2.8 into (3).
1 tank + 1 box = 4
1 tank + 2.8 = 4
1 tank = 4 - 2.8 = 1.2
Mass of 1 tank = 1.2 kg
Mass of 1 tank less than 1 box
= 2.8 - 1.2
= 1.6 kg
Answer(s): (a) 4 kg; (b) 22.4 kg; (c) 1.6 kg