You need to arrange three 7 and mathematical symbols to form number 1?

If 21x = 79x, what is the value of x?

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?