- A18 = 9 + 9
- B18 = 5 + 13
- C18 = 6 + 12
- D18 = 1 + 17
Step-by-Step Solution
5 and 13 are both prime and 5 + 13 = 18. In the others 9, 6, 12 and 1 are not prime.
Answer: B) 18 = 5 + 13
Goldbach noticed that many even numbers can be written as a sum of two primes.
Which of these is a correct way to write 18 as the sum of two prime numbers?
Class 6Prime and Composite NumbersPlaying with Numbers
Master this chapter in 30 minutes a day.
Don't just memorise the answer — build a daily practice habit.
Practice 5 Similar Questions Free →All Prime and Composite Numbers practice questions
More Class 6 Prime and Composite Numbers practice
In a class in Jaipur, students stand in a rectangular grid. The teacher says only a…Two whole numbers are co-prime if their only common factor is 1. Lakshmi picks the…A number between 30 and 40 is prime, and the sum of its digits is 4. What is the number?Deepa says: 'If a number ends in 5 and is bigger than 5, it must be composite.' Is Deepa…Karan thinks of a two-digit number. Both of its digits are prime digits (chosen from 2,…