You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

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

What can you serve, but never eat?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

Why is a river so rich ?

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 ?

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?

I am quite hot but become too cold if you remove the first two letters. What am I?

1. What does:
TIM JOB
represent?

2. What does:
MO_ _
represent?

What is next number in the pattern below:

131 517 192 123 ?