Originally posted by knptmug at 2005-4-20 09:47 PM:# E" z8 m! U- X& r( k$ ~
set small watermelon: x, middle watermelon y and big watermeton z* `$ {- s) _; }1 n1 ?6 w* O
6 \; H/ p) q; O) `/ d3 P B
two simultaneous equations are set up: . x& w ^- g2 o3 q; _6 S0.5x+2y+5z=50 (1)$ V* F q6 N3 H9 w
x+y+z=50 (2)3 q! | B! m' T, h' x3 c4 W5 M5 W9 g, c
Equation(1) means that the total amount paid is equal t ...