Let number of articles produced on a particular day =x
`because` Cost of production of each article `=RS.(2x+3)`
According to given condition
`x(2x+3)=90`
`implies2x^(2)+3x=90`
`implies2x^(2)+(15-12)x-90=0`
`implies2x^(2)+15-12x-90=0`
`impliesx(2x+15)-6(2x+15)=0`
`implies(x-6)(2x+15)=0`
when `x-6=0impliesx=6`
and `2x+15=0impliesx=(-15)/(2)`
`"Hence", x=6" "(because"no . of articles cannot be negative")`
So, the number of articles produced is 6 and the cost of each article is `(2xx6+3)=RS.15`.