在含盐10%的450克盐水中,再放入50克水,那么新盐水的含盐率是 .
5: ==0.25= %
2.5÷ ==15: = %= (小数)
÷8==0.375=9÷ =; 填质数:21= + ; = × .
= %=2÷ =四成.
14÷ == ÷ = (填小数)