The total mass of 4 tanks and 5 boxes was 10.9 kg.
The total mass of 6 tanks and 6 boxes was 14.4 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)
4 tanks + 5 boxes = 10.9 --- (1)
6 tanks + 6 boxes = 14.4 --- (2)
(2)
÷ 6 1 tank + 1 box = 2.4 --- (3)
Mass of 1 tank and 1 box = 2.4 kg
(b)
(3) x 4
4 tanks + 4 boxes = 4 x 2.4
4 tanks + 4 boxes = 9.6 --- (4)
(1) - (4)
(4 tanks + 5 tanks) - (4 tanks + 4 tanks) = 10.9 - 9.6
4 tanks - 4 tanks + 5 boxes - 4 boxes = 1.3
1 box = 1.3
9 boxes = 1.3 x 9 = 11.7
Mass of 9 boxes = 11.7 kg
(c)
Substitute 1 box = 1.3 into (3).
1 tank + 1 box = 2.4
1 tank + 1.3 = 2.4
1 tank = 2.4 - 1.3 = 1.1
Mass of 1 tank = 1.1 kg
Mass of 1 tank less than 1 box
= 1.3 - 1.1
= 0.2 kg
Answer(s): (a) 2.4 kg; (b) 11.7 kg; (c) 0.2 kg