Calculate the percentage composition in terms of mass of solution obtained by mixing `300 g` of a `25%` and `400 g` of a `40%` solution by mass.

Answer

`31.9%`

Explanation

Mass of `25% sol A =(25)/(100)xx300=75g`
mass of `40% sol B (40)/(100)xx400=160g`
`%` composition of `A`
`=(75xx100)/(75+160)=(75xx100)/(235)=31.9%`
`%` composition of `B=100-31.9 = 68.1%`