The total mass of 5 boxes and 6 tanks was 47.2 kg.
The total mass of 4 boxes and 4 tanks was 34 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)
5 boxes + 6 tanks = 47.2 --- (1)
4 boxes + 4 tanks = 34 --- (2)
(2)
÷ 4 1 box + 1 tank = 8.5 --- (3)
Mass of 1 box and 1 tank = 8.5 kg
(b)
(3) x 5
5 boxes + 5 tanks = 5 x 8.5
5 boxes + 5 tanks = 42.5 --- (4)
(1) - (4)
(5 boxes + 6 tanks) - (5 boxes + 5 tanks) = 47.2 - 42.5
5 boxes - 5 boxes + 6 tanks - 5 tanks = 4.7
1 tank = 4.7
9 tanks = 4.7 x 9 = 42.3
Mass of 9 tanks = 42.3 kg
(c)
Substitute 1 tank = 4.7 into (3).
1 box + 1 tank = 8.5
1 box + 4.7 = 8.5
1 box = 8.5 - 4.7 = 3.8
Mass of 1 box = 3.8 kg
Mass of 1 box less than 1 tank
= 4.7 - 3.8
= 0.9 kg
Answer(s): (a) 8.5 kg; (b) 42.3 kg; (c) 0.9 kg