The total mass of 3 boxes and 4 tanks was 11.7 kg.
The total mass of 4 boxes and 4 tanks was 13.2 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)
3 boxes + 4 tanks = 11.7 --- (1)
4 boxes + 4 tanks = 13.2 --- (2)
(2)
÷ 4 1 box + 1 tank = 3.3 --- (3)
Mass of 1 box and 1 tank = 3.3 kg
(b)
(3) x 3
3 boxes + 3 tanks = 3 x 3.3
3 boxes + 3 tanks = 9.9 --- (4)
(1) - (4)
(3 boxes + 4 tanks) - (3 boxes + 3 tanks) = 11.7 - 9.9
3 boxes - 3 boxes + 4 tanks - 3 tanks = 1.8
1 tank = 1.8
8 tanks = 1.8 x 8 = 14.4
Mass of 8 tanks = 14.4 kg
(c)
Substitute 1 tank = 1.8 into (3).
1 box + 1 tank = 3.3
1 box + 1.8 = 3.3
1 box = 3.3 - 1.8 = 1.5
Mass of 1 box = 1.5 kg
Mass of 1 box less than 1 tank
= 1.8 - 1.5
= 0.3 kg
Answer(s): (a) 3.3 kg; (b) 14.4 kg; (c) 0.3 kg