Isotope $"$Y$"($a short lived nuclide$)$ and $"$Z$"($a longer lived nuclide$)$ are mixed in a sample, and each has two very different half lives. The plot below gives the fraction of isotopes $"$Y$"$ and $"$Z$"$ remaining in the mixed sample versus time in hours

Estimate the half lifes of isotopes $"$Y$"$ and $"$Z$"$ using the mixture plot. State untits.