2yards to 45 feet as a fraction in simplest form

Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining bismuth-210 transforms into another atom (polonium-210 in this case) each day. if you begin with 233 mg of bismuth-210, how much remains after 8 days?

According to the general equation for conditional probability if p(anb)=3/7 and p(b)=7/8 what is p(a i b)

If you eat 4 medium strawberries, you get 48% of your daily recommenced amount of vitamin c. what fraction of your daily amount of vitamin c do you still need?