What's the best place to go shopping in the ocean?

Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???

I look at you, you look at me I raise my right, you raise your left. What am I?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

What kind of storm is always in a rush?

Two old friends, Jack and Bill, meet after a long time.

Three kids
Jack: Hey, how are you, man?
Bill: Not bad, got married and I have three kids now.
Jack: That's awesome. How old are they?
Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.
Jack: Cool..But I still don't know.
Bill: My eldest kid just started taking piano lessons.
Jack: Oh, now I get it.

How old are Bill's kids?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

Can you move 2 matchsticks to form four equal sized squares.

There are 3 apples in the basket and you take away 2. How many apples do you have now?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?