In one auditorium there are 420 seats, and in the second - 480. In the first hall, compared to the second, there are 5 rows less, but in each row of the first hall there are 10 seats less than in each row of the second. How many seats does each row of the first hall have.

Step-by-step explanation:

Let there be x row is first hall

then in 2nd hall number of rows will be = x+5

Let there be y seats in each row of the first hall

then, there would be y+10 seats in each row of the 2nd hall.

Therefore, according to question

(y+10)(x+5) =480(i)

and  xy = 420(ii)

Solve these two equations you will get the required number of seats in each row of the first hall have.

you answer is a

step-by-step explanation: