The total mass of 4 boxes and 5 tanks was 24.5 kg.
The total mass of 5 boxes and 5 tanks was 27 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 9 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
4 boxes + 5 tanks = 24.5 --- (1)
5 boxes + 5 tanks = 27 --- (2)
(2)
÷ 5 1 box + 1 tank = 5.4 --- (3)
Mass of 1 box and 1 tank = 5.4 kg
(b)
(3) x 4
4 boxes + 4 tanks = 4 x 5.4
4 boxes + 4 tanks = 21.6 --- (4)
(1) - (4)
(4 boxes + 5 tanks) - (4 boxes + 4 tanks) = 24.5 - 21.6
4 boxes - 4 boxes + 5 tanks - 4 tanks = 2.9
1 tank = 2.9
9 tanks = 2.9 x 9 = 26.1
Mass of 9 tanks = 26.1 kg
(c)
Substitute 1 tank = 2.9 into (3).
1 box + 1 tank = 5.4
1 box + 2.9 = 5.4
1 box = 5.4 - 2.9 = 2.5
Mass of 1 box = 2.5 kg
Mass of 1 box less than 1 tank
= 2.9 - 2.5
= 0.4 kg
Answer(s): (a) 5.4 kg; (b) 26.1 kg; (c) 0.4 kg