The total mass of 2 tanks and 3 boxes was 15.9 kg.
The total mass of 5 tanks and 5 boxes was 29 kg.
- What is the mass of 1 tank and 1 box?
- What is the mass of 7 boxes?
- How much less is the mass of 1 box than 1 tank?
(a)
2 tanks + 3 boxes = 15.9 --- (1)
5 tanks + 5 boxes = 29 --- (2)
(2)
÷ 5 1 tank + 1 box = 5.8 --- (3)
Mass of 1 tank and 1 box = 5.8 kg
(b)
(3) x 2
2 tanks + 2 boxes = 2 x 5.8
2 tanks + 2 boxes = 11.6 --- (4)
(1) - (4)
(2 tanks + 3 tanks) - (2 tanks + 2 tanks) = 15.9 - 11.6
2 tanks - 2 tanks + 3 boxes - 2 boxes = 4.3
1 box = 4.3
7 boxes = 4.3 x 7 = 30.1
Mass of 7 boxes = 30.1 kg
(c)
Substitute 1 box = 4.3 into (3).
1 tank + 1 box = 5.8
1 tank + 4.3 = 5.8
1 tank = 5.8 - 4.3 = 1.5
Mass of 1 tank = 1.5 kg
Mass of 1 tank less than 1 box
= 4.3 - 1.5
= 2.8 kg
Answer(s): (a) 5.8 kg; (b) 30.1 kg; (c) 2.8 kg