The total mass of 4 boxes and 5 tanks was 25.7 kg.
The total mass of 5 boxes and 5 tanks was 28.5 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 5 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
4 boxes + 5 tanks = 25.7 --- (1)
5 boxes + 5 tanks = 28.5 --- (2)
(2)
÷ 5 1 box + 1 tank = 5.7 --- (3)
Mass of 1 box and 1 tank = 5.7 kg
(b)
(3) x 4
4 boxes + 4 tanks = 4 x 5.7
4 boxes + 4 tanks = 22.8 --- (4)
(1) - (4)
(4 boxes + 5 tanks) - (4 boxes + 4 tanks) = 25.7 - 22.8
4 boxes - 4 boxes + 5 tanks - 4 tanks = 2.9
1 tank = 2.9
5 tanks = 2.9 x 5 = 14.5
Mass of 5 tanks = 14.5 kg
(c)
Substitute 1 tank = 2.9 into (3).
1 box + 1 tank = 5.7
1 box + 2.9 = 5.7
1 box = 5.7 - 2.9 = 2.8
Mass of 1 box = 2.8 kg
Mass of 1 box less than 1 tank
= 2.9 - 2.8
= 0.1 kg
Answer(s): (a) 5.7 kg; (b) 14.5 kg; (c) 0.1 kg