What has 13 hearts but no other organs?

The Puzzle: A girl, a boy, and a dog start walking down a road.

They start at the same time, from the same point, in the same direction.

The boy walks at 5 km/h, the girl at 6 km/h.

The dog runs from boy to girl and back again with a constant speed of 10 km/h. The dog does not slow down on the turn.
How far does the dog travel in 1 hour?

What is the fastest way to double your money?

By what process could you make a 'Tea-Table' into food?

How many Watermelons are there in the below picture?

Solve the equation in the image by looking at the pattern closely.

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

I’m tall when I’m young, and I’m short when I’m old. What am I?

A bag contains 64 balls of eight different colours. There are eight of each colour (including red). What is the least number you would have to pick, without looking, to be sure of selecting 3 red balls?

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?