The total mass of 3 boxes and 4 tanks was 23.6 kg.
The total mass of 4 boxes and 4 tanks was 26.4 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 7 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
3 boxes + 4 tanks = 23.6 --- (1)
4 boxes + 4 tanks = 26.4 --- (2)
(2)
÷ 4 1 box + 1 tank = 6.6 --- (3)
Mass of 1 box and 1 tank = 6.6 kg
(b)
(3) x 3
3 boxes + 3 tanks = 3 x 6.6
3 boxes + 3 tanks = 19.8 --- (4)
(1) - (4)
(3 boxes + 4 tanks) - (3 boxes + 3 tanks) = 23.6 - 19.8
3 boxes - 3 boxes + 4 tanks - 3 tanks = 3.8
1 tank = 3.8
7 tanks = 3.8 x 7 = 26.6
Mass of 7 tanks = 26.6 kg
(c)
Substitute 1 tank = 3.8 into (3).
1 box + 1 tank = 6.6
1 box + 3.8 = 6.6
1 box = 6.6 - 3.8 = 2.8
Mass of 1 box = 2.8 kg
Mass of 1 box less than 1 tank
= 3.8 - 2.8
= 1 kg
Answer(s): (a) 6.6 kg; (b) 26.6 kg; (c) 1 kg