i) Consider number of boys =x and number of girls =y. According to the question,x+y=10or, y=10−x ………(i)y=x+4 ………..(ii) x 1 23  4y 9 8 7 6 x1  2 3 4 y 5 6 7 8Graphical solution : Girls =7, boys =3(ii) Consider price of a pencil is x and price of a pen is y. According to the question,5x+7y=50.....(i)7x+5y=46 .….(ii) x 1 2 3 4 y 7.8 6.4 5 4.2 x 1 2 3 4y 6.4 5.7 54.2Graphical solution : Price of a pencil is Rs 3Price of a pen is Rs 5.