The total mass of 2 boxes and 3 tanks was 21.4 kg.
The total mass of 4 boxes and 4 tanks was 33.2 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 = 21.4 --- (1)
4 boxes + 4 tanks = 33.2 --- (2)
(2)
÷ 4 1 box + 1 tank = 8.3 --- (3)
Mass of 1 box and 1 tank = 8.3 kg
(b)
(3) x 2
2 boxes + 2 tanks = 2 x 8.3
2 boxes + 2 tanks = 16.6 --- (4)
(1) - (4)
(2 boxes + 3 tanks) - (2 boxes + 2 tanks) = 21.4 - 16.6
2 boxes - 2 boxes + 3 tanks - 2 tanks = 4.8
1 tank = 4.8
8 tanks = 4.8 x 8 = 38.4
Mass of 8 tanks = 38.4 kg
(c)
Substitute 1 tank = 4.8 into (3).
1 box + 1 tank = 8.3
1 box + 4.8 = 8.3
1 box = 8.3 - 4.8 = 3.5
Mass of 1 box = 3.5 kg
Mass of 1 box less than 1 tank
= 4.8 - 3.5
= 1.3 kg
Answer(s): (a) 8.3 kg; (b) 38.4 kg; (c) 1.3 kg