1.1+3.3+5.5+7.7+9.9+11.11+13.13+15.15

问题描述:

1.1+3.3+5.5+7.7+9.9+11.11+13.13+15.15

1.1(1+3+5+7+9) + 1.01(11+13+15)
=1.1 * 25 + 1.01 *39
=27.5+ 39.39
=66.89