(d) Let the pencil of brand A = x and brand B = y. According to the question x + y = 20.......(i) Cost of brand A pencil =₹4.50 per piece Cost of brand B pencil = ₹ 6 per piece Total amount spent by Suraj = ₹ 111 ⇒ 4.50x +6y =₹111......(ii) Solving Eqs. (i) and (ii), we get x=6 , y = 14 He bought 14 pencils of brand B.