$l_{31}=l_{30}\,p_{30}$ with $p_{30}=e_{30}/(1+e_{31})$

Given that the complete expectation of life at ages 30 and 31 for a particular group are 21.39 and 20.91 years and that the number living at age 30 is 41176, what is the number of people that attains the age 31?