amy and jed are among the 35 people,who are standing the other ,waiting to buy movie ticket.The number of people in front of amy plus the number of people behind jed is 24.if their are 15 people behind amy ,including jed,how many people are in front of jed?计算了好几次都是29人,答案是31 ,求教大家以及各位大神,在此谢过!