The first 3 multiples of 7 are: 7, 14, and 21.
The unit digit of 3127173 is the unit digit of 7173. The other digits of 3127 are multiples of 10 and so they cannot contribute to the unit digit. Now the unit digits of the powers of 7 are Power -- Unit digit 0 -- 1 1 -- 7 2 -- 9 3 -- 3 4 -- 1 and you are back into the loop (of 1-7-9-3). So, you only need consider 7 to the power 173 modulo 4. That is, the remainder when 173 is divided by 4. 173 = 1 mod 4 So the unit digit of 3127173 is the same as the unit digit of 7173 which is the unit digit of 71 which is 7.
All multiples of their LCM is divisible by them. lcm(8, 7, 6, 5, 4, 3, 2, 1) = 840 therefore need the largest multiple of 840 which is a 3-digit number = 840 x 1 = 840.
-5
Oh, dude, you want common multiples of 3 and 7 up to 100? Well, let me break it down for you. The common multiples of 3 and 7 are numbers that both 3 and 7 can divide evenly into. So, the common multiples of 3 and 7 up to 100 are 21, 42, 63, and 84. Like, that's it.
The smallest 3-digit multiple of 7 is 105 = 15*7 The largest 3-digit multiple of 7 is 994 = 142*7 So there are 142-14 = 128 3-digit multiples of 7, ie 128 3-digit numbers that are divisible by 7.
There are 13 two-digit multiples of 7.
There are 600 such numbers.
No two digit prime number exists that is a multiple of 7. All two digit numbers that are multiples of 7 are compositenumbers.
Multiples of 3 are 3, 6, 9 and so on. Multiples of 7 are 7, 14, 21 and so on. The common multiples of 3 and 7 include 21, 42, 63 and so on.
The first 3 multiples of 7 are: 7, 14, and 21.
42 is the LCM of 3, 6 and 7. All multiples of 42 are multiples of 3, 6 and 7
The unit digit of 3127173 is the unit digit of 7173. The other digits of 3127 are multiples of 10 and so they cannot contribute to the unit digit. Now the unit digits of the powers of 7 are Power -- Unit digit 0 -- 1 1 -- 7 2 -- 9 3 -- 3 4 -- 1 and you are back into the loop (of 1-7-9-3). So, you only need consider 7 to the power 173 modulo 4. That is, the remainder when 173 is divided by 4. 173 = 1 mod 4 So the unit digit of 3127173 is the same as the unit digit of 7173 which is the unit digit of 71 which is 7.
Since all 3 are prime numbers LCM = 3 * 5 * 7 = 105 All multiples of 105 are multiples of 3, 5 and 7
The common multiples of 3 and 7 are 21, 42, 63 and so on.
The LCM of 3 and 7 is 21
70 and 75