The total mass of 3 boxes and 4 tanks was 25.1 kg.
The total mass of 5 boxes and 5 tanks was 35 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)
3 boxes + 4 tanks = 25.1 --- (1)
5 boxes + 5 tanks = 35 --- (2)
(2)
÷ 5 1 box + 1 tank = 7 --- (3)
Mass of 1 box and 1 tank = 7 kg
(b)
(3) x 3
3 boxes + 3 tanks = 3 x 7
3 boxes + 3 tanks = 21 --- (4)
(1) - (4)
(3 boxes + 4 tanks) - (3 boxes + 3 tanks) = 25.1 - 21
3 boxes - 3 boxes + 4 tanks - 3 tanks = 4.1
1 tank = 4.1
8 tanks = 4.1 x 8 = 32.8
Mass of 8 tanks = 32.8 kg
(c)
Substitute 1 tank = 4.1 into (3).
1 box + 1 tank = 7
1 box + 4.1 = 7
1 box = 7 - 4.1 = 2.9
Mass of 1 box = 2.9 kg
Mass of 1 box less than 1 tank
= 4.1 - 2.9
= 1.2 kg
Answer(s): (a) 7 kg; (b) 32.8 kg; (c) 1.2 kg