2) There are a b c d individuals in categories A, B, C and D, so there are (1) A+B+C =134 (2) B+C+D =131(3) A+D =

From (1)+(2)-(3), it can be concluded that b+c=88, then d+d=89, so a+b+c+d= 177.

3) The unit price of flour is X yuan,15x+35 *1/2x = 31.2x =10.4 yuan, and you can figure out how much each one costs.

4) If x meters can be woven, it is 8/6/4= 10/7.5/x, and if x=4, it is 4 meters.