An author received Tk. 80 in royalties for each of the first 1,00,000 copies of her book sold and Tk. 60 in royalties for each additional copy sold. If she received a total of Tk. 2,60,000 I royalties, how many copies of her book were sold?
সঠিক উত্তর: Option D
let, total sold books = x here, .80 X 100000 + .60 X (x-100000) = 260000 or,80000+ .60x - 60000=260000 or. x= (260000-20000)/.60 = 4,00,000