Calculate solubility of `BasO_(4)` when `CaSO_(4)` and `BasO_(4)` are dissolved in water simultaneously `K_(sp)` of `CaSO_(4)=p.K_(sp)` of `BasO_(4)=q` and simultaneous solubility of `CaSO_(4)` is `b` mol/litre.

Explanation

`bq//p`
For `BasO_(4)`
`[Ba^(2+)][SO_(4)^(+)]=K_(sp)` of `BaSO_(4)=q`
For `CaSO_(4)`
`[Ca^(2+)][SO_(4)^(2-)]=K_(sp) of CaSO_(4)=p`
`([Ba^(2+)])/([Ca^(2+)])=(q)/(p)rArr [Ba^(2+)]=(bq)/(p)`