The total mass of 3 tanks and 4 boxes was 26.9 kg.
The total mass of 5 tanks and 5 boxes was 37.5 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)
3 tanks + 4 boxes = 26.9 --- (1)
5 tanks + 5 boxes = 37.5 --- (2)
(2)
÷ 5 1 tank + 1 box = 7.5 --- (3)
Mass of 1 tank and 1 box = 7.5 kg
(b)
(3) x 3
3 tanks + 3 boxes = 3 x 7.5
3 tanks + 3 boxes = 22.5 --- (4)
(1) - (4)
(3 tanks + 4 tanks) - (3 tanks + 3 tanks) = 26.9 - 22.5
3 tanks - 3 tanks + 4 boxes - 3 boxes = 4.4
1 box = 4.4
5 boxes = 4.4 x 5 = 22
Mass of 5 boxes = 22 kg
(c)
Substitute 1 box = 4.4 into (3).
1 tank + 1 box = 7.5
1 tank + 4.4 = 7.5
1 tank = 7.5 - 4.4 = 3.1
Mass of 1 tank = 3.1 kg
Mass of 1 tank less than 1 box
= 4.4 - 3.1
= 1.3 kg
Answer(s): (a) 7.5 kg; (b) 22 kg; (c) 1.3 kg