Question

Let’s start with a simple one. What comes next in this sequence of prime numbers? 11, 13, 17, 19, ?

Answer 1

This sequence is of prime numbers . Do you know about prime number ?
obviously , A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. 
for example : 2 , 3, 5, 7, 11, 13, 17, 19, 23 , ......

in series 11, 13, 17, 19, ? prime numbers are in regular forms .so tell me what comes after 19? but you have to choose number only in prime number.
of course next prime number is not other than 23. because it is a natural number that has no positive integer other than 1 and itself.

answer should be 23.

Answer 2

What is a prime number:

= > A number which is having 2 factors (or) The numbers which cannot be divided evenly by any other number except 1 and itself.

Ex: 1,2,3,5,7,11,13,19,23,29.....

Now,

Given sequence is 11,13,17,19.

Given numbers are consecutive prime numbers which lies between 11 to 20.

The next number in the sequence cannot be 20 because it has more than 2 factors{1,2,4,5,10,20}

The next number in the sequence cannot be 21 because it has more than 2 factors{1,3,7,21}

The next number cannot be 22 because it has 3 factors{1,2,11,22}

Therefore, the next numbers will be 23. because it don't have any factors other than 1 and itself.

Therefore, the next number in the sequence will be 23.

Hope it helps!