A mixture of quantity of Milk with 16 L of water is worth 90

[gmatter2012]

A mixture of quantity of Milk with 16 L of water is worth 90 $/L .
If Pure Milk cost 108 $/L , what is the amount of milk in the mixture ?

[coolhabhi]

Let water cost be 0. Then by allegarion rule :
=>0 108
_____90
=>18 90

so Water : Milk = 18 : 90
W : M = 1 : 5
since water is 16L, Milk will be 16*5 = 80L.