Homework #15.29

[arif_latif_2G]

Can someone walk me through this question:
For the first-order reaction A -> 3 B + C, when [A]0 = 0.015 mol x L^-1, the concentration of B increases to 0.018 mol x L^-1 in 3.0 min. (a) What is the rate constant for the reaction expressed as the rate of loss of A? (b) How much more time would be needed for the concentration of B to increase to 0.030 mol x L^-1?

[Riya Shah 4H]

(a) Since it is a first-order reaction, the rate constant k=[A]^1 and in terms of loss of A, you can just put a negative sign and say that it is decreasing.

(b) I am not sure about this one but would like to know the answer.