Here are some blue,white and black balls.The sum of the white and the blue balls is 10,and the sum

题目

Here are some blue,white and black balls.The sum of the white and the blue balls is 10,and the sum
of the blue and black ones is 7,the black and the white ones is 5.How many balls of each color?

答案

一共有(10+7+5)/2=11
black 11-10=1
white 11-7=4
blue11-5=6