Each week Manhattan GMAT posts a GMAT question on our blog and follows up with the answer the next day. Are you up for the challenge?
Every digit of a number written in binary is either 0 or 1. To translate a number from binary, multiply the nth digit (reading from right to left) by 2n-1. For instance, 1101 = (1 × 23) + (1 × 22) + (0 × 21) + (1 × 20) = 25. What is the largest prime number (written in binary) that is a factor of both 100010000 and 1000100000 ?
(A) 10
(B) 11
(C) 101
(D) 1011
(E) 10001