What is 45x3,679= what is the sum

Carlos has 4/5 of a tank of fuel in his car. he uses 1/10 of a tank per day. how many days will his fuel last?

What percent of the circle below is shaded?

Nick has box brads. he uses 4 brads for the first project. nick let’s b represent the original number of brads and finds that for the second project, the number of brads he uses is 8 more than half the difference of b and 4. write an expression to represent the number of brads he uses for the second project.