The total mass of 5 boxes and 6 tanks was 47.4 kg.
The total mass of 6 boxes and 6 tanks was 51 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)
5 boxes + 6 tanks = 47.4 --- (1)
6 boxes + 6 tanks = 51 --- (2)
(2)
÷ 6 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) = 47.4 - 42.5
5 boxes - 5 boxes + 6 tanks - 5 tanks = 4.9
1 tank = 4.9
8 tanks = 4.9 x 8 = 39.2
Mass of 8 tanks = 39.2 kg
(c)
Substitute 1 tank = 4.9 into (3).
1 box + 1 tank = 8.5
1 box + 4.9 = 8.5
1 box = 8.5 - 4.9 = 3.6
Mass of 1 box = 3.6 kg
Mass of 1 box less than 1 tank
= 4.9 - 3.6
= 1.3 kg
Answer(s): (a) 8.5 kg; (b) 39.2 kg; (c) 1.3 kg