The total mass of 3 tanks and 4 boxes was 10.6 kg.
The total mass of 6 tanks and 6 boxes was 18 kg.
- What is the mass of 1 tank and 1 box?
- What is the mass of 7 boxes?
- How much less is the mass of 1 box than 1 tank?
(a)
3 tanks + 4 boxes = 10.6 --- (1)
6 tanks + 6 boxes = 18 --- (2)
(2)
÷ 6 1 tank + 1 box = 3 --- (3)
Mass of 1 tank and 1 box = 3 kg
(b)
(3) x 3
3 tanks + 3 boxes = 3 x 3
3 tanks + 3 boxes = 9 --- (4)
(1) - (4)
(3 tanks + 4 tanks) - (3 tanks + 3 tanks) = 10.6 - 9
3 tanks - 3 tanks + 4 boxes - 3 boxes = 1.6
1 box = 1.6
7 boxes = 1.6 x 7 = 11.2
Mass of 7 boxes = 11.2 kg
(c)
Substitute 1 box = 1.6 into (3).
1 tank + 1 box = 3
1 tank + 1.6 = 3
1 tank = 3 - 1.6 = 1.4
Mass of 1 tank = 1.4 kg
Mass of 1 tank less than 1 box
= 1.6 - 1.4
= 0.2 kg
Answer(s): (a) 3 kg; (b) 11.2 kg; (c) 0.2 kg