Test: Prime numbers - Year 6 MCQ

Prime numbers are natural numbers greater than 1 that have no positive divisors other than 1 and themselves. Among the given options, 2 is the smallest prime number.

A prime number has exactly two distinct positive divisors: 1 and itself. 9 is not a prime number because it has divisors other than 1 and 9 (specifically, 1, 3, and 9).

The prime numbers between 10 and 20 are 11, 13, 17, and 19, making a total of 4 prime numbers in this range.

To find the next prime number after 31, we look for the smallest prime number greater than 31, which is 37.

53 is a prime number because it has no divisors other than 1 and 53 itself.

The prime number just before 50 is 47.

The first 5 prime numbers are 2, 3, 5, 7, and 11. Their sum is 2 + 3 + 5 + 7 + 11 = 28.

The prime numbers between 40 and 50 are 41, 43, and 47.

The only even prime number is 2. All other prime numbers are odd.

Prime numbers greater than 50 and less than 70 are: 53, 59, 61, and 67

• Hence, number of primes between 50 and 70: 4