What has many keys but can’t open a single lock?

I know there are two methods by using three time the same number with a plus(+) operator , you can make sum as 60.

One of them is 20+20+20.

whats the other way ?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

What jumps when it walks and sits when it stands?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?

Which point will the car reach to go out?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

Which Burger Is Different in below image?

The more you take me, the more you leave me behind.
Who Am I?