题目有问题,只好将错就错
2×5分之1+3×5分之1+8×11分之1+……+20×23分之1
=1/10+1/15+(1/8+1/11+1/11-1/14+……+1/20-1/23)/3
=1/6+(1/8-1/23)/3
=1/6+5/184
=107/552
题目有问题,只好将错就错
2×5分之1+3×5分之1+8×11分之1+……+20×23分之1
=1/10+1/15+(1/8+1/11+1/11-1/14+……+1/20-1/23)/3
=1/6+(1/8-1/23)/3
=1/6+5/184
=107/552