Please help me find the percent by mass in the following:

1. Hydrogen in retinol, C20H29OHC20H29OH, also known as vitamin A

2. Hydrogen in ammonium sulfate, (NH4)2SO4(NH4)2SO4, a substance used as a nitrogen fertilizer

3. Platinum in PtI2(NH3)2

4. Oxygen in the female sex hormone estradiol, C18H24O2

5. Carbon in capsaicin, C18H27NO3C18H27NO3, the compound that gives the hot taste to chili peppers