On the basis of this , some annuities and life annuities with certain interest rate are more discussed . the property of m power of the present value about the discrete and continuous annuities is found as well as some recursion formulae and differential equations about some life annuities 在此基础上，一方面对确定利率下的一些(生存)年金作了进一步地讨论，得到了某些离散和连续年金现值的m ( m 2的整数)次方性质及一些离散生存年金精算现值的递推方程和一些连续生存年金精算现值所满足的微分方程。
The number of possible combinations is thus twelve to the twelfth , meaning that we shall have to choose from a total of eight thousand eight hundred and seventy - four billion , two hundred and ninety - six million , six hundred and seventy - two thousand , two hundred and fifty - six potential solutions 想想吧，四个人物，两两组对就有12种可能性，再算上列出的12项关系，可能发生的组合就是12的12次方，即8874296672256 （译者注：正确答案应该是8916100448256 ；原文如此）种潜在的方案。
