The total mass of 3 boxes and 4 tanks was 28.1 kg.
The total mass of 6 boxes and 6 tanks was 48 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 9 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
3 boxes + 4 tanks = 28.1 --- (1)
6 boxes + 6 tanks = 48 --- (2)
(2)
÷ 6 1 box + 1 tank = 8 --- (3)
Mass of 1 box and 1 tank = 8 kg
(b)
(3) x 3
3 boxes + 3 tanks = 3 x 8
3 boxes + 3 tanks = 24 --- (4)
(1) - (4)
(3 boxes + 4 tanks) - (3 boxes + 3 tanks) = 28.1 - 24
3 boxes - 3 boxes + 4 tanks - 3 tanks = 4.1
1 tank = 4.1
9 tanks = 4.1 x 9 = 36.9
Mass of 9 tanks = 36.9 kg
(c)
Substitute 1 tank = 4.1 into (3).
1 box + 1 tank = 8
1 box + 4.1 = 8
1 box = 8 - 4.1 = 3.9
Mass of 1 box = 3.9 kg
Mass of 1 box less than 1 tank
= 4.1 - 3.9
= 0.2 kg
Answer(s): (a) 8 kg; (b) 36.9 kg; (c) 0.2 kg