The total mass of 5 boxes and 6 tanks was 45.5 kg.
The total mass of 6 boxes and 6 tanks was 49.2 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)
5 boxes + 6 tanks = 45.5 --- (1)
6 boxes + 6 tanks = 49.2 --- (2)
(2)
÷ 6 1 box + 1 tank = 8.2 --- (3)
Mass of 1 box and 1 tank = 8.2 kg
(b)
(3) x 5
5 boxes + 5 tanks = 5 x 8.2
5 boxes + 5 tanks = 41 --- (4)
(1) - (4)
(5 boxes + 6 tanks) - (5 boxes + 5 tanks) = 45.5 - 41
5 boxes - 5 boxes + 6 tanks - 5 tanks = 4.5
1 tank = 4.5
9 tanks = 4.5 x 9 = 40.5
Mass of 9 tanks = 40.5 kg
(c)
Substitute 1 tank = 4.5 into (3).
1 box + 1 tank = 8.2
1 box + 4.5 = 8.2
1 box = 8.2 - 4.5 = 3.7
Mass of 1 box = 3.7 kg
Mass of 1 box less than 1 tank
= 4.5 - 3.7
= 0.8 kg
Answer(s): (a) 8.2 kg; (b) 40.5 kg; (c) 0.8 kg