The total mass of 2 boxes and 3 tanks was 10.8 kg.
The total mass of 4 boxes and 4 tanks was 16.4 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)
2 boxes + 3 tanks = 10.8 --- (1)
4 boxes + 4 tanks = 16.4 --- (2)
(2)
÷ 4 1 box + 1 tank = 4.1 --- (3)
Mass of 1 box and 1 tank = 4.1 kg
(b)
(3) x 2
2 boxes + 2 tanks = 2 x 4.1
2 boxes + 2 tanks = 8.2 --- (4)
(1) - (4)
(2 boxes + 3 tanks) - (2 boxes + 2 tanks) = 10.8 - 8.2
2 boxes - 2 boxes + 3 tanks - 2 tanks = 2.6
1 tank = 2.6
7 tanks = 2.6 x 7 = 18.2
Mass of 7 tanks = 18.2 kg
(c)
Substitute 1 tank = 2.6 into (3).
1 box + 1 tank = 4.1
1 box + 2.6 = 4.1
1 box = 4.1 - 2.6 = 1.5
Mass of 1 box = 1.5 kg
Mass of 1 box less than 1 tank
= 2.6 - 1.5
= 1.1 kg
Answer(s): (a) 4.1 kg; (b) 18.2 kg; (c) 1.1 kg