Question 775637: which is the least number when divided by 4,6,8,12,&16 leaves a remainder of 2
Answer by Edwin McCravy(20060) (Show Source):
You can put this solution on YOUR website!
Actually the answer is 2, but that's not the answer your teacher
expects. But it is correct. If you divide 2 by any integer larger
than it is, you get the remainder 2.
0 0 0 0 0
4)2 6)2 8)2 12)2 16)2
0 0 0 0 0
2 2 2 2 2
So it always leaves a remainder of 2.
But I'll bet your teacher expects one larger than 2 itself.
----------------------------------------------
So Let the number be N
which is the least number > 2 that when divided by 4,6,8,12,&16 leaves a
remainder of 2
So
N = 4a+2 = 6b+2 = 8b+2 = 12c+2 = 16d+2
Subtract 2 from each of those
N-2 = 4a = 6b = 8b = 12c = 16d
Therefore N-2 must be a multiple of 4,6,8,12, and 16, so it is
the least common multiple of 4,6,8,12, and 16.
4 = 2×2
6 = 2 ×3
8 = 2×2×2
12 = 2×2 ×3
16 = 2×2×2×2
---------------
LCM = 2×2×2×2×3 = 48
The least common multiple of those is 48
So N-2 = 48
Therefore N = 50.
Edwin
|
|
|