Question

Seventy five trees were planted in rows and columns to form a rectangle
by the factory owner to keep environment air pollution free. The number of the rows is 10
less than the number of columns.
i) What is the number of columns?​

Answer 1

Answer: 15

Step-by-step explanation: Let the no. of columns be 'x'

No. of rows= x-10

x*(x-10) = 75

x²-10x-75=0

x²-15x+5x-75=0

x(x-15) +5(x-15)=0

(x+5)(x-15)=0

x= -5, 15

As number of columns cannot be negative, therefore

Number of columns=x=15