The total mass of 3 boxes and 4 tanks was 26.4 kg.
The total mass of 6 boxes and 6 tanks was 44.4 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 10 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
3 boxes + 4 tanks = 26.4 --- (1)
6 boxes + 6 tanks = 44.4 --- (2)
(2)
÷ 6 1 box + 1 tank = 7.4 --- (3)
Mass of 1 box and 1 tank = 7.4 kg
(b)
(3) x 3
3 boxes + 3 tanks = 3 x 7.4
3 boxes + 3 tanks = 22.2 --- (4)
(1) - (4)
(3 boxes + 4 tanks) - (3 boxes + 3 tanks) = 26.4 - 22.2
3 boxes - 3 boxes + 4 tanks - 3 tanks = 4.2
1 tank = 4.2
10 tanks = 4.2 x 10 = 42
Mass of 10 tanks = 42 kg
(c)
Substitute 1 tank = 4.2 into (3).
1 box + 1 tank = 7.4
1 box + 4.2 = 7.4
1 box = 7.4 - 4.2 = 3.2
Mass of 1 box = 3.2 kg
Mass of 1 box less than 1 tank
= 4.2 - 3.2
= 1 kg
Answer(s): (a) 7.4 kg; (b) 42 kg; (c) 1 kg