5
9
13
11
Answer is Wrong!
Answer is Right!
The missing number is 11.
The numbers in the sequence are all prime numbers, and they are increasing by 2 each time. The first number is 7, and the second number is 11. Therefore, the missing number is 11.
A prime number is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number.
The first 25 prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, and 89.