Which number should replace the question mark?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

Replace the question mark with the correct number in the below-given picture?

What has a bottom at the top?

Akbar called Birbal and asked him to draw a line on the floor. He asked Birbal to make that line smaller without erasing it. Birbal smiled and did it before Akbar could blink his eyes.

How did he managed to do it?

What does this below rebus puzzle mean?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

Five teams were competing in cricket where they faced each other exactly once. After the tournament, the following is the point table.

DareDevils 6
SuperKings 5
Royals 4
Sunrisers 2
Riders ?

How many points did Riders end up with?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?