The total mass of 5 boxes and 6 tanks was 36.9 kg.
The total mass of 4 boxes and 4 tanks was 25.6 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 = 36.9 --- (1)
4 boxes + 4 tanks = 25.6 --- (2)
(2)
÷ 4 1 box + 1 tank = 6.4 --- (3)
Mass of 1 box and 1 tank = 6.4 kg
(b)
(3) x 5
5 boxes + 5 tanks = 5 x 6.4
5 boxes + 5 tanks = 32 --- (4)
(1) - (4)
(5 boxes + 6 tanks) - (5 boxes + 5 tanks) = 36.9 - 32
5 boxes - 5 boxes + 6 tanks - 5 tanks = 4.9
1 tank = 4.9
9 tanks = 4.9 x 9 = 44.1
Mass of 9 tanks = 44.1 kg
(c)
Substitute 1 tank = 4.9 into (3).
1 box + 1 tank = 6.4
1 box + 4.9 = 6.4
1 box = 6.4 - 4.9 = 1.5
Mass of 1 box = 1.5 kg
Mass of 1 box less than 1 tank
= 4.9 - 1.5
= 3.4 kg
Answer(s): (a) 6.4 kg; (b) 44.1 kg; (c) 3.4 kg