Find the greatest number of 5 digit exactly divisible by 2,4,6,8,10?
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In number theory remember one fact every positive integer is a multiple of prime number(s) else it can't exist.
The Least Common Multiple of these 5 digits (2,4,6,8,10) is the multiple of highest power of every prime number that occurs in the set (2,4,6,8,10).
So 2 has just 1 prime factor 2 itself
4 has prime factor 2 raised to the power 2 times i.e 22
6 has prime factors 2,3 each to the power 1
8 has prime factor 2 raised to the power 3 times i.e 23
10 has prime factors 2 and 5 each to the power 1 time.
So all the prime numbers that occured are 2, 3, 5 with factors powers 3, 1, 1 so Least common multiple is 23x31x51 = 8 x 3 x 5 = 120.
So the highest 5 digit number divisible by the set (2,4,6,8,10) should also be a multiple of 120. We know the highest 5 digit number is 10000 i.e 104 . So just divide and see the remainder, that would be the highest divisible 5 digit number as Pallv Sahu mentioned 99960
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Answer:
Find the greatest number of 5 digit exactly divisible by 2,4,6,8,10?
Experience your favorite novels through audiobooks on Audible.
In number theory remember one fact every positive integer is a multiple of prime number(s) else it can't exist.
The Least Common Multiple of these 5 digits (2,4,6,8,10) is the multiple of highest power of every prime number that occurs in the set (2,4,6,8,10).
So 2 has just 1 prime factor 2 itself
4 has prime factor 2 raised to the power 2 times i.e 22
6 has prime factors 2,3 each to the power 1
8 has prime factor 2 raised to the power 3 times i.e 23
10 has prime factors 2 and 5 each to the power 1 time.
So all the prime numbers that occured are 2, 3, 5 with factors powers 3, 1, 1 so Least common multiple is 23x31x51 = 8 x 3 x 5 = 120.
So the highest 5 digit number divisible by the set (2,4,6,8,10) should also be a multiple of 120. We know the highest 5 digit number is 10000 i.e 104 . So just divide and see the remainder, that would be the highest divisible 5 digit number as Pallv Sahu mentioned 99960