The total mass of 5 tanks and 6 boxes was 40.7 kg.
The total mass of 4 tanks and 4 boxes was 28.8 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)
5 tanks + 6 boxes = 40.7 --- (1)
4 tanks + 4 boxes = 28.8 --- (2)
(2)
÷ 4 1 tank + 1 box = 7.2 --- (3)
Mass of 1 tank and 1 box = 7.2 kg
(b)
(3) x 5
5 tanks + 5 boxes = 5 x 7.2
5 tanks + 5 boxes = 36 --- (4)
(1) - (4)
(5 tanks + 6 tanks) - (5 tanks + 5 tanks) = 40.7 - 36
5 tanks - 5 tanks + 6 boxes - 5 boxes = 4.7
1 box = 4.7
9 boxes = 4.7 x 9 = 42.3
Mass of 9 boxes = 42.3 kg
(c)
Substitute 1 box = 4.7 into (3).
1 tank + 1 box = 7.2
1 tank + 4.7 = 7.2
1 tank = 7.2 - 4.7 = 2.5
Mass of 1 tank = 2.5 kg
Mass of 1 tank less than 1 box
= 4.7 - 2.5
= 2.2 kg
Answer(s): (a) 7.2 kg; (b) 42.3 kg; (c) 2.2 kg