Which sequence is geometric and has `1/4` as its fifth term and `1/2' as the common ratio?
O A..., 1, 1/2", 1/4", 1/8"...
B..., `1/4,' 1/2,' '1, 2, ...
O C.., 1/72", 1/36', '1/18', '1/9 ,...
OD..., 8,' '4,' '2,' 1,'

Long division setup showing an incomplete calculation. 12 is in the divisor, 6839 is in the dividend, and 5 hundreds and 6 tens is written in the quotient. 6000 is subtracted from 6839 to give 839. an unknown value represented by a box is being subtracted from 839. what number should be placed in the box to complete the division calculation?