Question

Concrete is made by mixing screenings cement and sand in the ratio 3 : 1 :
15 how much sand would be needed to make 125 terms of concrete

Answer 1

let  screenings be 3x

let cement be x

let sand be 15x

3x+x+15x = 125

19 x= 125

x=125/9

or 13.8888888889

3x= 125/9 x 3

= 125/3

15x = 125/9 x 15

= 208.3333