Q: The ratio of boys to girls in a classroom is 3:5. If there are 4 more girls than boys, how many students are in the classroom?
A: Since the ratio of boys to girls is 3:5, then the class is divided into 3 + 5 = 8 parts. The girls have 5 - 3 = 2 parts more than the boys. Since 2 parts are equal to 4, then 1 part is equal to 4 / 2 = 2 students. Hence, there are 8 parts x 2 = 16 students. The answer is 16.

Q: A class has 32 students and they all need to present their projects. Every period is 40 minutes long. How many periods will it take for every student to present their project if they have 5 minutes to do so?
A: All the students will present their projects in 32 * 5 = 160 minutes. It will take 160 / 40 = 4 periods for all the students to present their projects. The answer is 4.

Q: Melissa wants to make some dresses to sell at the upcoming festival. She has 56 square meters of fabric to make them. She knows that each dress takes 4 square meters of fabric and 3 hours to make. How many hours does she have to work?
A:
Each dress takes 4 square meters of fabric to make, so the number of dresses she can make will be 56 / 4 = 14 dresses. Each dress takes 3 hours to make, thus she will have to work 14 dresses x 3 hours / dress = 42 hours. The answer is 42.