The total mass of 2 boxes and 3 tanks was 12.4 kg.
The total mass of 5 boxes and 5 tanks was 22.5 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 8 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
2 boxes + 3 tanks = 12.4 --- (1)
5 boxes + 5 tanks = 22.5 --- (2)
(2)
÷ 5 1 box + 1 tank = 4.5 --- (3)
Mass of 1 box and 1 tank = 4.5 kg
(b)
(3) x 2
2 boxes + 2 tanks = 2 x 4.5
2 boxes + 2 tanks = 9 --- (4)
(1) - (4)
(2 boxes + 3 tanks) - (2 boxes + 2 tanks) = 12.4 - 9
2 boxes - 2 boxes + 3 tanks - 2 tanks = 3.4
1 tank = 3.4
8 tanks = 3.4 x 8 = 27.2
Mass of 8 tanks = 27.2 kg
(c)
Substitute 1 tank = 3.4 into (3).
1 box + 1 tank = 4.5
1 box + 3.4 = 4.5
1 box = 4.5 - 3.4 = 1.1
Mass of 1 box = 1.1 kg
Mass of 1 box less than 1 tank
= 3.4 - 1.1
= 2.3 kg
Answer(s): (a) 4.5 kg; (b) 27.2 kg; (c) 2.3 kg