The total mass of 5 boxes and 6 tanks was 19.9 kg.
The total mass of 4 boxes and 4 tanks was 14.4 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 = 19.9 --- (1)
4 boxes + 4 tanks = 14.4 --- (2)
(2)
÷ 4 1 box + 1 tank = 3.6 --- (3)
Mass of 1 box and 1 tank = 3.6 kg
(b)
(3) x 5
5 boxes + 5 tanks = 5 x 3.6
5 boxes + 5 tanks = 18 --- (4)
(1) - (4)
(5 boxes + 6 tanks) - (5 boxes + 5 tanks) = 19.9 - 18
5 boxes - 5 boxes + 6 tanks - 5 tanks = 1.9
1 tank = 1.9
8 tanks = 1.9 x 8 = 15.2
Mass of 8 tanks = 15.2 kg
(c)
Substitute 1 tank = 1.9 into (3).
1 box + 1 tank = 3.6
1 box + 1.9 = 3.6
1 box = 3.6 - 1.9 = 1.7
Mass of 1 box = 1.7 kg
Mass of 1 box less than 1 tank
= 1.9 - 1.7
= 0.2 kg
Answer(s): (a) 3.6 kg; (b) 15.2 kg; (c) 0.2 kg