The total mass of 3 boxes and 4 tanks was 23.6 kg.
The total mass of 6 boxes and 6 tanks was 37.8 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)
3 boxes + 4 tanks = 23.6 --- (1)
6 boxes + 6 tanks = 37.8 --- (2)
(2)
÷ 6 1 box + 1 tank = 6.3 --- (3)
Mass of 1 box and 1 tank = 6.3 kg
(b)
(3) x 3
3 boxes + 3 tanks = 3 x 6.3
3 boxes + 3 tanks = 18.9 --- (4)
(1) - (4)
(3 boxes + 4 tanks) - (3 boxes + 3 tanks) = 23.6 - 18.9
3 boxes - 3 boxes + 4 tanks - 3 tanks = 4.7
1 tank = 4.7
9 tanks = 4.7 x 9 = 42.3
Mass of 9 tanks = 42.3 kg
(c)
Substitute 1 tank = 4.7 into (3).
1 box + 1 tank = 6.3
1 box + 4.7 = 6.3
1 box = 6.3 - 4.7 = 1.6
Mass of 1 box = 1.6 kg
Mass of 1 box less than 1 tank
= 4.7 - 1.6
= 3.1 kg
Answer(s): (a) 6.3 kg; (b) 42.3 kg; (c) 3.1 kg