Find the greatest numbers of 5 digit which is exactly divisible by 12,rand 4

If lmn=xyz, which congruences are true by cpctc? check all that apply

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

What is the difference between regular convex and concave polygons