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

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

In a mathematical quiz, you are asked the following question:

Use three 9s in a mathematical expression without dividing or multiplying to form the number one.

Can you answer the question?

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

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

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

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?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

Find out the missing number in the picture attached: