这个题 思路上自己有个矛盾点

NO.PZ2018062016000008 问题如下 Mr Swhannuity whipayments occurs the beginning of eayear. The annuity hannuinterest rate of 5%, eapayment is $500 anlast for 10 years. The present value of the annuity is closest to: A.$3897.99 B.$4053.91 C.$4216.07 B is correct. Put the calculator in the BGN mo, input tN=10, I/Y=5, PMT=500, FV=0, calculate the PV=-4053.91. Therefore the present value of the annuity is $4053.91. 为什么这里的FV可以按成0来算？

NO.PZ2018062016000008 $4053.91 $4216.07 B is correct. Put the calculator in the BGN mo, input tN=10, I/Y=5, PMT=500, FV=0, calculate the PV=-4053.91. Therefore the present value of the annuity is $4053.91. 这道题判断BGN的那个关键词就是the beginning of the year对吗？ 还有那些关键词可以判断其是先付年金呢？除了明确写出annuity e的

$4053.91 $4216.07 B is correct. Put the calculator in the BGN mo, input tN=10, I/Y=5, PMT=500, FV=0, calculate the PV=-4053.91. Therefore the present value of the annuity is $4053.91.老师我设置BGN模式总是算不出来正确的数。我算出来总是-4907.6，为什么啊 好奇怪，好几道题都这样。