The total mass of 2 tanks and 3 boxes was 21.4 kg.
The total mass of 4 tanks and 4 boxes was 34 kg.
- What is the mass of 1 tank and 1 box?
- What is the mass of 9 boxes?
- How much less is the mass of 1 box than 1 tank?
(a)
2 tanks + 3 boxes = 21.4 --- (1)
4 tanks + 4 boxes = 34 --- (2)
(2)
÷ 4 1 tank + 1 box = 8.5 --- (3)
Mass of 1 tank and 1 box = 8.5 kg
(b)
(3) x 2
2 tanks + 2 boxes = 2 x 8.5
2 tanks + 2 boxes = 17 --- (4)
(1) - (4)
(2 tanks + 3 tanks) - (2 tanks + 2 tanks) = 21.4 - 17
2 tanks - 2 tanks + 3 boxes - 2 boxes = 4.4
1 box = 4.4
9 boxes = 4.4 x 9 = 39.6
Mass of 9 boxes = 39.6 kg
(c)
Substitute 1 box = 4.4 into (3).
1 tank + 1 box = 8.5
1 tank + 4.4 = 8.5
1 tank = 8.5 - 4.4 = 4.1
Mass of 1 tank = 4.1 kg
Mass of 1 tank less than 1 box
= 4.4 - 4.1
= 0.3 kg
Answer(s): (a) 8.5 kg; (b) 39.6 kg; (c) 0.3 kg