The total mass of 2 boxes and 3 tanks was 10 kg.
The total mass of 4 boxes and 4 tanks was 15.6 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 = 10 --- (1)
4 boxes + 4 tanks = 15.6 --- (2)
(2)
÷ 4 1 box + 1 tank = 3.9 --- (3)
Mass of 1 box and 1 tank = 3.9 kg
(b)
(3) x 2
2 boxes + 2 tanks = 2 x 3.9
2 boxes + 2 tanks = 7.8 --- (4)
(1) - (4)
(2 boxes + 3 tanks) - (2 boxes + 2 tanks) = 10 - 7.8
2 boxes - 2 boxes + 3 tanks - 2 tanks = 2.2
1 tank = 2.2
6 tanks = 2.2 x 6 = 13.2
Mass of 6 tanks = 13.2 kg
(c)
Substitute 1 tank = 2.2 into (3).
1 box + 1 tank = 3.9
1 box + 2.2 = 3.9
1 box = 3.9 - 2.2 = 1.7
Mass of 1 box = 1.7 kg
Mass of 1 box less than 1 tank
= 2.2 - 1.7
= 0.5 kg
Answer(s): (a) 3.9 kg; (b) 13.2 kg; (c) 0.5 kg