Write and solve a proportion to answer the question, What number is 80% of 65

Acollection of coins has value of 64 cents. there are two more nickels than dimes and three times as many pennies as dimes in this collection. how many of each kind of coin are in the collection?

Given a: b and b: c, find a: b: c. write the ratio in simplest form. a: b=6: 10 and b: c=21: 33

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