The total mass of 3 boxes and 4 tanks was 14.5 kg.
The total mass of 6 boxes and 6 tanks was 24 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 8 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
3 boxes + 4 tanks = 14.5 --- (1)
6 boxes + 6 tanks = 24 --- (2)
(2)
÷ 6 1 box + 1 tank = 4 --- (3)
Mass of 1 box and 1 tank = 4 kg
(b)
(3) x 3
3 boxes + 3 tanks = 3 x 4
3 boxes + 3 tanks = 12 --- (4)
(1) - (4)
(3 boxes + 4 tanks) - (3 boxes + 3 tanks) = 14.5 - 12
3 boxes - 3 boxes + 4 tanks - 3 tanks = 2.5
1 tank = 2.5
8 tanks = 2.5 x 8 = 20
Mass of 8 tanks = 20 kg
(c)
Substitute 1 tank = 2.5 into (3).
1 box + 1 tank = 4
1 box + 2.5 = 4
1 box = 4 - 2.5 = 1.5
Mass of 1 box = 1.5 kg
Mass of 1 box less than 1 tank
= 2.5 - 1.5
= 1 kg
Answer(s): (a) 4 kg; (b) 20 kg; (c) 1 kg