How is the moon similar to a dollar?

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT

What 5-letter word typed in all capital letters can be read the same upside down?

I have branches, but no fruit, trunk or leaves. What am I?

What does this below rebus puzzle mean?

How can you take 2 from 5 and leave 4?

I have one of the three numbers: 1, 2, or 3 in my mind. I speak only truth. You can ask me just one question for which I will only reply in yes or no or don't know. What question will you ask from me so that you are able to know the number?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

What number divided by 4 is the same as that number minus 4?