Respuesta :

the ratio is 4:3:1
let the ratio be 4x:3x:x
according to the question,4x+3x+x=40
8x=40
x=5
therefore amount of gravel=x*4=5*4=20[tex]m^{3}[/tex]
amount of sand=5*3=15[tex]m^{3}[/tex]
amount of cement=5*1=5[tex]m^{3}[/tex]