Question

Students of a school were made to stand in rows for drill. If 3 students less were standing in each rows , 10more rows were required and if 5 students more were standing in each row then the number of rows was reduced by 10 Find the number of students participating in the drill ?

Can you answer this question please !!​

Answer 1

Answer:

Step-by-step explanation:

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

Then total students will be=x*y

Now according to question

(x+10)(y-3)=xy

xy-3x+10y-30=xy

10y-3x=30-----------------(eq1)

Now..

(x-10)(y+5)=xy

xy+5x-10y-50=xy

5x-10y=50 ---------------(eq 2)

Adding eq 1 and 2 we get

2x=80

x=40

Putting x=40 in eq 1 we get

10y-120=30

10y=150

y=15

total no=x*y=600

Answer 2

Step-by-step explanation:

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

So, the total number of students = xy.

(i)

3 students less were standing in each row. 10 more rows were required.

⇒ (y - 3)(x + 10) = xy

⇒ xy + 10y - 3x - 30 = xy

⇒ -3x + 10y = 30

⇒ 3x - 10y = -30   ------ (1)

(ii)

Given, 5 more students were standing then the numbers of rows were reduced by 10.

⇒ (y + 5)(x - 10) = xy

⇒ xy - 10y + 5x - 50 = xy

⇒ 5x - 10y = 50    ------ (2)

On solving (1) & (2), we get

⇒ 3x - 10y = -30

⇒ 5x - 10y = 50

   -------------------

    -2x = -80

       x = 40.

Substitute x = 40 in (1), we get

⇒ 3x - 10y = -30

⇒ 3(40) - 10y = -30

⇒ 120 - 10y = -30

⇒ -10y = -30 - 120

⇒ y = 15.

Therefore, number of students = xy = 600.

Hope this helps!