由1,3,5,7,9,11,13,15,17,19十个数组成甲组数,由2,4,6,8,10,12,14,16,18,20组成乙组数,分别由甲组数与乙组数各取一数相加,共可得到不同和的个数多少?
问题描述:
由1,3,5,7,9,11,13,15,17,19十个数组成甲组数,由2,4,6,8,10,12,14,16,18,20组成乙组数,分别由甲组数与乙组数各取一数相加,共可得到不同和的个数多少?
答
21,23,25,27,29,31,33,35,37,39共10个.