Question

16. A group or sOldiers was asked to fall in line making rows of three. It was found that there was one soldier extra. Then they were asked to stand in rows of five. It was found there were left 2 soldiers. They were asked to stand in rows of seven. Then there were three soldiers who could not be adjusted. At least how many soldiers were there in the group?​

Answer 1

Step-by-step explanation:

Let the number of rows be x rows and the number of students in each row be y students .

Then the total number of students in a class =xy students.

∴ According to the question ,

(x−2)(y+1)=xy

⇒xy+x−2y−2=xy

x−2y=2⟶(i)

And

(x+3)(y−1)=xy

⇒xy−x+3y−3=xy

−x+3y=3⟶(ii)

x−2y=2

−x+3y=3

On adding , y=5 students.

putting the value of y in equation ⟶(i)

x−2(5)=2

x=12 rows.

∴ Total number of students in a classroom =(12×5)students =60 students.