I need help with this

The second term of an arithmetic sequence is 30. the fifth term is 90.calculatei). the commor difference of the sequence ii). the first term of the sequence tje first, second and fifth terms of the arithmetic sequence are the first three terms of a geometric sequence calculate the seventh term of the geometric sequence

45(x-7)=90 what would the value of c on this equation be?

In a study, the sample is chosen by putting people's names on a dartboard, and blindly throwing darts to select 5 names. what is the sampling method?