The total mass of 5 tanks and 6 boxes was 28.5 kg.
The total mass of 4 tanks and 4 boxes was 20 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 = 28.5 --- (1)
4 tanks + 4 boxes = 20 --- (2)
(2)
÷ 4 1 tank + 1 box = 5 --- (3)
Mass of 1 tank and 1 box = 5 kg
(b)
(3) x 5
5 tanks + 5 boxes = 5 x 5
5 tanks + 5 boxes = 25 --- (4)
(1) - (4)
(5 tanks + 6 tanks) - (5 tanks + 5 tanks) = 28.5 - 25
5 tanks - 5 tanks + 6 boxes - 5 boxes = 3.5
1 box = 3.5
9 boxes = 3.5 x 9 = 31.5
Mass of 9 boxes = 31.5 kg
(c)
Substitute 1 box = 3.5 into (3).
1 tank + 1 box = 5
1 tank + 3.5 = 5
1 tank = 5 - 3.5 = 1.5
Mass of 1 tank = 1.5 kg
Mass of 1 tank less than 1 box
= 3.5 - 1.5
= 2 kg
Answer(s): (a) 5 kg; (b) 31.5 kg; (c) 2 kg