The total mass of 4 boxes and 5 tanks was 41.6 kg.
The total mass of 6 boxes and 6 tanks was 55.2 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 9 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
4 boxes + 5 tanks = 41.6 --- (1)
6 boxes + 6 tanks = 55.2 --- (2)
(2)
÷ 6 1 box + 1 tank = 9.2 --- (3)
Mass of 1 box and 1 tank = 9.2 kg
(b)
(3) x 4
4 boxes + 4 tanks = 4 x 9.2
4 boxes + 4 tanks = 36.8 --- (4)
(1) - (4)
(4 boxes + 5 tanks) - (4 boxes + 4 tanks) = 41.6 - 36.8
4 boxes - 4 boxes + 5 tanks - 4 tanks = 4.8
1 tank = 4.8
9 tanks = 4.8 x 9 = 43.2
Mass of 9 tanks = 43.2 kg
(c)
Substitute 1 tank = 4.8 into (3).
1 box + 1 tank = 9.2
1 box + 4.8 = 9.2
1 box = 9.2 - 4.8 = 4.4
Mass of 1 box = 4.4 kg
Mass of 1 box less than 1 tank
= 4.8 - 4.4
= 0.4 kg
Answer(s): (a) 9.2 kg; (b) 43.2 kg; (c) 0.4 kg