Original quantity of dye and water in the original solution i.e., 16 litres (i.e. =40×
2
5
) and 24 litres (i.e. =40−16 ) Quantity of water added =16 litres (As 1 part =8 litres). Quantity of dye and water removed =
1
4
×
2
7
(56) i.e., 4 litres and
1
4
×
5
7
×(56) i.e., 10 litres. Final quantity of dye and water is 12 litres and 30 litres. ∴ Quantity of dye to be added to make the ratio of dye and water again 2:3 i.e., 8 litres.