Can someone help with these two problems and explain how you got it?

1. For a reaction with the stoichiometry, A + 2B --> 3P, write an expression that relates the rate of disappearance of A to the rate of disappearance of B and another expression that relates the disappearance of A to rate of appearance of P.

2. For a reaction with the stoichiometry of A + B + C --> P, a study of the initial rate of reaction revealed that the amount of time for formation of 1% of the total amount of possible product quartered when the concentration of A quadrupled, did not change when the concentration of B was halved, and doubled when the concentration of C was halved. Write a rate expression for this reaction and suggest a stepwise mechanism for the reaction.