Let the cost of one pencil, one notebook and one eraser be x,y and z respectively. Then, according to the question, 5x+6y+7z=250 . . . (i) and 6x+4y+2z=180 . . . (ii) 6× Eq. (i) −5× Eq. (ii) 30x+36y+42z=1500 30x+20y+10z=900 dividing the equation by 8 , we get 2y+4z=75 Hence, the cost of 2 notebooks and 4 erasers is ₹75.