Latest other Aptitude Question SOLUTION: find the sum of the smallest three prime factors of 6^22-1

• Placement Papers
• /
• other
• /
• Numerical Ability

other Question Papers:

(#M40039626) OTHER Numerical Ability question solve Keep an EYE

find the sum of the smallest three prime factors of 6^22-1

Asked In other Harsh Poddar (9 years ago)

Unsolved Read Solution (1)

Is this Puzzle helpful?   (0)   (0) Submit Your Solution

Read Solution (1) :

BHASKAR MANDAL  (9 years ago)

first take the prime factors of the number 22
ie, 22 = 2*11
now consider, 6^2-1 = 35 = 5 * 7
so, the first two prime factors are 5 and 7
e.g, 6^(2*2)-1 = 1295 has a factors of 5 and 7, so on
it is true for all the even power of 6

for the next number you have to check the prime factors of 6^11 , which is not possible to do. so there is other way to find the nest number
there is a property of prime numbers
i.e, (x^(p-1)-1 )/ p = 0
where p is the prime number and x is any number less than p

in this case x=6 and p = 22+1 = 23

so the sum of all the prime numbers will be = 5+7+23 = 35

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.