The total mass of 2 boxes and 3 tanks was 16 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 9 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
2 boxes + 3 tanks = 16 --- (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 2
2 boxes + 2 tanks = 2 x 5.7
2 boxes + 2 tanks = 11.4 --- (4)
(1) - (4)
(2 boxes + 3 tanks) - (2 boxes + 2 tanks) = 16 - 11.4
2 boxes - 2 boxes + 3 tanks - 2 tanks = 4.6
1 tank = 4.6
9 tanks = 4.6 x 9 = 41.4
Mass of 9 tanks = 41.4 kg
(c)
Substitute 1 tank = 4.6 into (3).
1 box + 1 tank = 5.7
1 box + 4.6 = 5.7
1 box = 5.7 - 4.6 = 1.1
Mass of 1 box = 1.1 kg
Mass of 1 box less than 1 tank
= 4.6 - 1.1
= 3.5 kg
Answer(s): (a) 5.7 kg; (b) 41.4 kg; (c) 3.5 kg