Anybody know these. geometry

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?

What is the gcf of 20c^3-5c^4+30c^6

Moesha is (3g+1) years old and shanti is twice moesha age. find the sum of the ages of moesha and shanti in 2 years time. how old will shanti be when moeshas age in twice her present age? find how old moesha and shanti were 4 years ago if g= 5