Usual disclaimer, I am not smart enough to be the court jester, but I will try and answer the questions

Q1. Why doesn't Tarzan have a beard when he lives in the jungle without a razor?
A.   What was the question again, please

Q2. Why do we press harder on a remote control when we know the batteries are flat?
A.   To be sure, to be sure, that they are actually flat

Q3. Why do banks charge a fee on 'insufficient funds' when they know there is not enough?
A.   To stop the insufficient funds brigade, from flooding the bank accounts

Q4. Why do Kamikaze pilots wear helmets?
A.   So as not to give away their intentions, until the last moment

Q5. Why does someone believe you when you say there are four billion stars, but check when you say the paint is wet?
A.   Sometimes wet paint may look dry

Q6. Whose idea was it to put an 'S' in the word 'lisp'?
A.   Ye olde scribe, from the dark ages

Q7. Why is it that people say they 'slept like a baby when babies wake up every two hours?
A.   They may have been asleep, when the baby woke up

Q8. If the temperature is zero outside today and it's going to be twice as cold tomorrow, how cold will it be?
A.   Either -1ºC or 16ºF

Q9. Do married people live longer than single ones or does it only seem longer?
A.   It just seems longer

Q10. Why do people pay to go up tall buildings and then put money in binoculars to look at things on the ground?
A.     Without putting money in, the binoculars will not work

Q11. Who was the first person to look at a cow and say, 'I think I'll squeeze these pink dangly things here, and drink whatever comes out?'
A.     A long lost relative of Cheetah, who was a friend of Tarzan

Q12. Why do toasters always have a setting so high that could burn the toast to a horrible crisp, which no decent human being would eat?
A.     For those who like to toast frozen bread, and who like their toast, very well done

Q13. Why does your Gynaecologist leave the room when you get undressed?
A.    Not sure, but it must work, as there are always plenty of babies around

Q14. Why does Goofy stand erect while Pluto remains on all fours? They're both dogs!
A.     Goofy was always a showoff

Q15. If corn oil is made from corn, and vegetable oil is made from vegetables, then what is baby oil made from?
A.     Baby oil drops

Q16. If electricity comes from electrons, does morality come from morons?
A.     Yes, and no, but sometimes perhaps

Q17. Why do the Alphabet song and Twinkle, Twinkle Little Star have the same tune? Stop singing and read on......
A.     OK

Q18. Do illiterate people get the full effect of Alphabet Soup?
A.     No, not unless they know all 23 letters of the alphabet

Q19. Did you ever notice that when you blow in a dog's face, he gets mad at you, but when you take him on a car ride, he sticks his head out the window?
A.     Yes I have noticed that

Q20. Does pushing the elevator button more than once make it arrive faster?
A.     That question has finally got me stumped

Do I get a prize for trying to answer them all, or are you just going to laugh at me?