Question

A group of 5 students took 15 days to finish a project. After 9 days, 3 students left the group. How many days did it take the students to finish the project in this case?

Answer 1

Using proportions, it is found that it took 15 days for the students to finish the project.

What is a proportion?

A proportion is a fraction of a total amount, and the measures are related using a rule of three. Due to this, relations between variables, either direct or inverse proportional, can be built to find the desired measures in the problem.

In this problem, we have that:

• 100% of the project is done by 5 students in 15 days.

• After the 3 students left, 2 students will have a time of x days to do 100 - (9/15) = 40% of the project.

The compound rule of three is given as follows:

1 project - 5 students - 15 days

0.4 project - 2 students - x days

Increasing the number of students, the number of days is reduced, hence the measures are inverse proportional and the rule of three is given by:

$\frac{15}{x} = \frac{2}[5} \times \frac{1}{0.4}$

$\frac{15}{x} = \frac{2}{2}$

15/x = 1

x = 15 days.

It took 15 days for the students to finish the project.

More can be learned about proportions at https://brainly.com/question/24372153

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