The total mass of 2 boxes and 3 tanks was 21.3 kg.
The total mass of 6 boxes and 6 tanks was 49.2 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 6 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
2 boxes + 3 tanks = 21.3 --- (1)
6 boxes + 6 tanks = 49.2 --- (2)
(2)
÷ 6 1 box + 1 tank = 8.2 --- (3)
Mass of 1 box and 1 tank = 8.2 kg
(b)
(3) x 2
2 boxes + 2 tanks = 2 x 8.2
2 boxes + 2 tanks = 16.4 --- (4)
(1) - (4)
(2 boxes + 3 tanks) - (2 boxes + 2 tanks) = 21.3 - 16.4
2 boxes - 2 boxes + 3 tanks - 2 tanks = 4.9
1 tank = 4.9
6 tanks = 4.9 x 6 = 29.4
Mass of 6 tanks = 29.4 kg
(c)
Substitute 1 tank = 4.9 into (3).
1 box + 1 tank = 8.2
1 box + 4.9 = 8.2
1 box = 8.2 - 4.9 = 3.3
Mass of 1 box = 3.3 kg
Mass of 1 box less than 1 tank
= 4.9 - 3.3
= 1.6 kg
Answer(s): (a) 8.2 kg; (b) 29.4 kg; (c) 1.6 kg