Can someone help me with this question and explain the answer, please?

Asequence of numbers begins with 12 and progresses geometrically. each number is the previous number divided by 2. which value can be used as the common ratio in an explicit formula that represents the sequence? 1/2 2 6 12

Simplify. (-2)^-3 a. -8 b. -1/8 c. 1/8 d. 8

If olu is twice as old as funmi if the sum of their ages is 60 how old is olu