Question 189470
1. 1/6,1/3,1/2,2/3


Sequence is arithmetic, common difference is d = 1/6 (subtract any term from next term to find it)



8,(?),20 


8+20=28 ---> 28/2=14


Missing number is 14


Sequence is 8, 14, 20  ----> arithmetic common difference d=6





3.5,(?),12.5


3.5+12.5=16 ---> 16/2 = 8


Missing # is 8


sequence: 3.5, 8, 12.5 ----> arithmetic common difference d=4.5