Question

a and b are two positive integers such that the least prime factor of a is 7 and the least prime factor of b is 11. Then, the least prime factor of (a + b) is​

Answer 1

Answer:

Given that, a is a positive integer and 7 is least prime factor of a.

Also, b is a positive integer and 11 is least prime factor of b.

Since, least prime factor of a is 7 it implies that a is an odd number.

Simillarly b is also an odd number and we know that

odd + odd = even

So, a+b= even

∴ The least prime factor of (a+b) is 2.

Answer 2

Answer:

2

Step-by-step explanation:

let a+b is a prime no. >2 and a+b must be odd

suppose a is even ,then least prime factor of a is 2, which is neither 3 nor 7.so that's why a+b cannot be even..

Therefore a+b cannot be a prime no. greater than 2

i.e., if least prime factor of a is 3 then b is 7..

Hence a+b=2