Question

Some children were lined up for school exercises
if 10 children had been raised less in each row then 3 rows have been increased. But if 10 students were increased to each row then 2 less rows are needed so how many students came for exercise

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Answer 1

Answer:

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.