The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

A cricket has 6 legs, a squirrel has 4 legs and a spider has 8 legs.

In a local zoo, it was found that the total number of legs is 612. Also, there are equal number of each of the above animals/insects.

Can you find out how many animals are there in the zoo?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

We know that the number 7 is the prime followed by a cube. Which next number is also a prime followed by a cube?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

There is a number which when you multiply by 3 and subtract 2 from the result, then the resulting number is the reverse of the actual number.

What is the smallest number that stands true on the statement?

In a basket of apples,
when counted in twos, there was one extra
when counted in threes, there were two extra when counted in fours, there were three extra
when counted in fives, there were four extra
when counted in sixes, there was five extra.

However, if the apples were counted in sevens, no extra apple was left. Can you calculate the minimum number of apples that were present in the basket?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

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

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?