Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?

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

which number am I?

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?

O_er_t_o_

Complete the missing letters of the given word.

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

In a guessing game, five friends had to guess the exact numbers of apples in a covered basket.
Friends guessed 22, 24, 29, 33, and 38, but none of the guesses was correct. The guesses were off by 1, 8, 6, 3, and 8 (in random order).

Can you determine the number of apples in a basket from this information?

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?