The total mass of 4 boxes and 5 tanks was 31.2 kg.
The total mass of 5 boxes and 5 tanks was 34.5 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 5 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
4 boxes + 5 tanks = 31.2 --- (1)
5 boxes + 5 tanks = 34.5 --- (2)
(2)
÷ 5 1 box + 1 tank = 6.9 --- (3)
Mass of 1 box and 1 tank = 6.9 kg
(b)
(3) x 4
4 boxes + 4 tanks = 4 x 6.9
4 boxes + 4 tanks = 27.6 --- (4)
(1) - (4)
(4 boxes + 5 tanks) - (4 boxes + 4 tanks) = 31.2 - 27.6
4 boxes - 4 boxes + 5 tanks - 4 tanks = 3.6
1 tank = 3.6
5 tanks = 3.6 x 5 = 18
Mass of 5 tanks = 18 kg
(c)
Substitute 1 tank = 3.6 into (3).
1 box + 1 tank = 6.9
1 box + 3.6 = 6.9
1 box = 6.9 - 3.6 = 3.3
Mass of 1 box = 3.3 kg
Mass of 1 box less than 1 tank
= 3.6 - 3.3
= 0.3 kg
Answer(s): (a) 6.9 kg; (b) 18 kg; (c) 0.3 kg