(57)+(911)=(55+6377)=(11877)bycomparison,a=7
Without adding, find the sum: (i) (1+3+5+7+9+11+13) (ii) (1+3+5+7+9+11+13+15+17+19) (iii) (1+3+5+7+9+11+13+15+17+19+21+23)