Math Riddles

If eight men can build eight walls in eight hours, how many men could build four walls in four hours?

If you divide 30 by half and add 10, what do you get?

Seven men have seven wives. Each wife has seven sacks. Each sack has seven cats. Each cat has seven kittens. How many legs are there in all?

I am a three-digit number. My tens digit is six more than my ones digit. My hundreds digit is eight less than my tens digit. What number am I?

Using only addition, add eight 8’s to get the number 1,000.

Two trains started simultaneously from stations A and B and proceeded towards each other. They met at a place 120 km away from station A. After meeting, they took 9 hours and 16 hours respectively to reach their destinations. What is the distance between stations A and B?

A man buys a horse for $60, sells it for $70, buys it back for $80, and finally sells it for $90. How much profit did he make?

A drawer contains 10 blue socks and 10 red socks. Without looking, how many socks must you take out to ensure you have a matching pair?

What shape has the most sides?

You have 9 identical looking balls but one weighs slightly more than the others. Using a balance scale, what’s the minimum number of weighings to find the heavier ball?