请大家看看这道鸡块的意思，意思都看不懂

先说莫名的第一道题：to the number 50，60and 70, weights arithmetic mean as w1, w2 and w3, the sum of them is 1, the mean is less than 60, which of the following is true?

Ⅰw1> w3

Ⅱw1< w3

Ⅲ w2=0

选项就是几个的组合

to the number 50，60and 70这句话的意识是不是50个数，60个数，70个数的意思？

有没有谁考到的出来补充一下？

The equations are :

w1+w2+w3 = 1;

50*w1 + 60*w2 + 70*w3 = 60