Question

On January 1st, Jerome concocts a rumor and tells Beth. On January 2nd, they each tell a new person. By the end of January 2nd, four people have heard the rumor. On each subsequent day, each person who has heard the rumor spreads it to a new person.
How many people have heard the rumor by the end of January 8th?

Answer 1

If we call 'D' the date in January, then at the end of D, there arr. 2^D people who have heard the rumor. 2^8 = 256 .