Answer:
The amount of sand builders need is 180 kg.
Step-by-step explanation:
It is given that the Bob the builder is making 480 kg on concrete mix. Concrete is made by mixing cement, sand and gravel in the ratio 1 : 3 : 4.
Let the amount of cement, sand and gravel is x, 3x and 4x respectively.
Since Bob the builder is making 480 kg on concrete mix, therefore
[tex]x+3x+4x=480[/tex]
[tex]8x=480[/tex]
Divide both sides by 8.
[tex]x=60[/tex]
The value of x is 60.
The amount of sand is 3x.
[tex]3x=3\times 60=180[/tex]
Therefore the amount of sand builders need is 180 kg.
