What does this simple rebus mean?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

Why do Chinese men eat more rice than Japanese men do ?

A maths symbol is hidden in the below Bar Graph. Can you decipher it?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

You walk into an old horror house. It has no power or plumbing. Once inside, you see three doors. Each door has a number on it. Behind each door is a way for you to die. Behind door number one, you die by getting eaten by a lion. Behind door number two, you die by getting murdered. Behind door number three, you die by an electric chair. You can’t turn back, so you have to go through a door. Which door do you go through?

What is the last thing you take off before bed?

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

Alex opened 24 presents
Jonah opened 8 presents
Clara opened 1 present

Can you find out how many presents were opened by Candy?

Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT