The total mass of 5 boxes and 6 tanks was 38 kg.
The total mass of 6 boxes and 6 tanks was 41.4 kg.
- What is the mass of 1 box and 1 tank?
- What is the mass of 7 tanks?
- How much less is the mass of 1 tank than 1 box?
(a)
5 boxes + 6 tanks = 38 --- (1)
6 boxes + 6 tanks = 41.4 --- (2)
(2)
÷ 6 1 box + 1 tank = 6.9 --- (3)
Mass of 1 box and 1 tank = 6.9 kg
(b)
(3) x 5
5 boxes + 5 tanks = 5 x 6.9
5 boxes + 5 tanks = 34.5 --- (4)
(1) - (4)
(5 boxes + 6 tanks) - (5 boxes + 5 tanks) = 38 - 34.5
5 boxes - 5 boxes + 6 tanks - 5 tanks = 3.5
1 tank = 3.5
7 tanks = 3.5 x 7 = 24.5
Mass of 7 tanks = 24.5 kg
(c)
Substitute 1 tank = 3.5 into (3).
1 box + 1 tank = 6.9
1 box + 3.5 = 6.9
1 box = 6.9 - 3.5 = 3.4
Mass of 1 box = 3.4 kg
Mass of 1 box less than 1 tank
= 3.5 - 3.4
= 0.1 kg
Answer(s): (a) 6.9 kg; (b) 24.5 kg; (c) 0.1 kg