Then, x+2y= 15( 1).

Country B: A chicken leg (1+20%) is X yuan, and a coke (1+20%) is Y yuan.

Then,1.2x+1.2y =15 (2)

Country C: A drumstick 1.2x( 1+20%), that is1.44x.

(1)(2) Simultaneous, x= 10, y=2.5.

So it takes 1.44 times 10 to buy a chicken leg in country C, which is equal to 14.4 yuan.

Math problems in primary schools are so difficult now. ...