Somebody gimme the answer ! it’s confusing..

Jabari is power washing houses for a summer job. for every job, he charges an initial fee plus $30 for each hour of work. his total fee for a 4 -hour job, for instance, is $170 . jabari's total fee,f, for a single job is a function of the number,t, of hours it takes him to complete the job. write the function's formula.

Is there an x intercept in the equation 60*1.15^x

Atown has a population of 7000 and grows at 3% every year. to the nearest year, how long will it be until the population will reach 12400?