Question

有7个连续奇数,第三个数与第七个数的和为42,这7个数分别是多少?

Answer 1

设这七个数是a,a+2,a+4,a+6,a+8,a+10,a+12;

由a+4+a+12=42得a=13,

故七个数是

13,15,17,19,21,23,25