The total mass of 4 tanks and 5 boxes was 30.3 kg.
The total mass of 5 tanks and 5 boxes was 32.5 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)
4 tanks + 5 boxes = 30.3 --- (1)
5 tanks + 5 boxes = 32.5 --- (2)
(2)
÷ 5 1 tank + 1 box = 6.5 --- (3)
Mass of 1 tank and 1 box = 6.5 kg
(b)
(3) x 4
4 tanks + 4 boxes = 4 x 6.5
4 tanks + 4 boxes = 26 --- (4)
(1) - (4)
(4 tanks + 5 tanks) - (4 tanks + 4 tanks) = 30.3 - 26
4 tanks - 4 tanks + 5 boxes - 4 boxes = 4.3
1 box = 4.3
7 boxes = 4.3 x 7 = 30.1
Mass of 7 boxes = 30.1 kg
(c)
Substitute 1 box = 4.3 into (3).
1 tank + 1 box = 6.5
1 tank + 4.3 = 6.5
1 tank = 6.5 - 4.3 = 2.2
Mass of 1 tank = 2.2 kg
Mass of 1 tank less than 1 box
= 4.3 - 2.2
= 2.1 kg
Answer(s): (a) 6.5 kg; (b) 30.1 kg; (c) 2.1 kg