懂英文和数学的来!百分数问题.

题目

懂英文和数学的来!百分数问题.
In alloy A and alloy B,there are 30% and 40% of iron in weight respectively.Now a new alloy is formed by 6 kg of alloy A and 2kg of alloy B.In the new alloy,
(a)what is the weight of iron?
(b)what percentage of weight is iron?

答案

a. the weight of iron: 6*30%+2*40%=2.6
b. iron percentage of weigh: 2.6/6*100%