Therefore m(t) = 50e-(In(2)):/1590 We could use the fact that el(2) = 2 to write the expression for m(t) in the alternative form m(t) = 50 * 2-1/1590 (b) The mass after 500 years is m(500) = 50e -500/1590 X = 80.4149 x mg (c) We want to find the value of t such that m(t) = 20, that is 50e-(In(2)) /1590 = 20 or e-(In(2)) t/1590 = 0.400 We solve this equation for t by taking the natural logarithm of both sides: In (2) 1590 0.2 X Thus (n(0.2) X Your answer cannot be t = understood or graded. More Information = (n( X Your answer cannot be -1590 understood or graded. More Information years In(2)