RRB NTPC Mains or Stage 2 Model Paper 4 with solutions

(d) 30 litres mixture contains 15 litres of water.When milk added to this, quentity of waterwill same in sance (i.e. 15 l).
Let xl of pure milk to be added, then 30% of
(30 + x) = 15
solve, x = 20