1. Profit and loss problem..

Two mercants sold a good of worth Rs 1000 from which one merchant A got profit from selling prices and merchant B got profit form cost price and profit for both is 25% what is difference amount.?

2.5lts solution bottles in which 4 lts of solution is filled in which 15 % of salt is mixed,1.5 lits solution is fell out and it is filled with water how much of salt content is present..?

3.Square of 21 cms and bull was tied at corner with rope of 7 cms how much area it can graze...

4.A and B can do a work 15 and 20 days respectively form which A as done half of the work and then b joind then it done 1/20th work how much many days in which a complted work which left by B.

Please can any one answer these question....