The total mass of 5 boxes and 6 tanks was 43.6 kg.
The total mass of 4 boxes and 4 tanks was 31.2 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)
5 boxes + 6 tanks = 43.6 --- (1)
4 boxes + 4 tanks = 31.2 --- (2)
(2)
÷ 4 1 box + 1 tank = 7.8 --- (3)
Mass of 1 box and 1 tank = 7.8 kg
(b)
(3) x 5
5 boxes + 5 tanks = 5 x 7.8
5 boxes + 5 tanks = 39 --- (4)
(1) - (4)
(5 boxes + 6 tanks) - (5 boxes + 5 tanks) = 43.6 - 39
5 boxes - 5 boxes + 6 tanks - 5 tanks = 4.6
1 tank = 4.6
5 tanks = 4.6 x 5 = 23
Mass of 5 tanks = 23 kg
(c)
Substitute 1 tank = 4.6 into (3).
1 box + 1 tank = 7.8
1 box + 4.6 = 7.8
1 box = 7.8 - 4.6 = 3.2
Mass of 1 box = 3.2 kg
Mass of 1 box less than 1 tank
= 4.6 - 3.2
= 1.4 kg
Answer(s): (a) 7.8 kg; (b) 23 kg; (c) 1.4 kg