CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

If the least prime factor of a number M is 3 and the least prime factor of another number N is 7, then the least prime factor of the number M+N is :


  1. 2

  2. 3

  3. 5

  4. 7

Open in App
Solution

The correct option is A

2


Least prime factor of a number m is 3

and the least prime factor of another number n is 7

Case 1: Let, any number whose least prime factor is 3.

A number will be always odd whose least factor is 3. Ex:3,9,15oddnumber

Therefore, m always be odd.

Case 2: Let, any number whose least prime factor is 7.

A number will be always odd whose least factor is 7. Ex:49,77oddnumber

Therefore, n always be odd. M+Nwillbealwayseven[Sumoftwooddnumberisalwayseven]Therefore,theleastfactorofM+Nwillbealwaysbe2.[Anynumberwhichisevenitsfactoris2]

Hence, the correct answer is option A.


flag
Suggest Corrections
thumbs-up
1
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Time and Speed
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon