4) Abe, Barb, Carl, Dee, and Earl all work at Thrifty's. Abe works every day,
Barb works every other day. Carl works every third day, Dee every fourth day, and
Earl every fifth day. Today they all worked together. How many days will it be
until they work together again?

Every 60 days.

Step-by-step explanation:

This is very similar to a sequence.

try starting out with:

Abe: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21

Barb:  2, 4, 6, 8, 10

Carl:  3, 6, 9, 12

Dee:  4,8, 12, 16, 20, 24, 28, 32, 36

Earl:  5, 10,

so If today they all worked together

We need a common multiple of  5, 4, 3  so  it is 60

It appears that it will be in 60 days