The task is to generate the correct answer for a given math problem.

Problem: a , b and c , each working alone can complete a job in 6 , 8 and 12 days respectively . if all three of them work together to complete a job and earn $ 1170 , what will be b ' s share of the earnings ?
$ 390

Problem: if one - third of one - fourth of a number is 18 , then 3 - tenth of that number is : a . 35
64.8

Problem: the tax on a commodity is diminished by 20 % but its consumption is increased by 10 % . find the decrease percent in the revenue derived from it ?

12 %