What happened when the wheel was invented?

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

What is the below Rebus indicate?

How many triangles can you find in this given picture?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

What is the next number in the series?

15 29 56 108 208 ?

Which number should replace the question mark?

What has 13 hearts but no other organs?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?