The given is that A B C D <span>x 4 = D C B A
</span><span>
Possible values of A are 1 or 2. It can't be 1 since the </span><span> </span><span>final result A is in unit place and 1 is not possible when we multiply any number by 4
</span><span>
2 B C D x </span><span>4 = </span><span>D C B 2</span>
It is clear above, that D = 8
2 B C 8 x <span>4 = </span><span>8 C B 2</span>
Possible values of B should be 1 or 2
We try B=1
2 1 C 8 x <span>4 = </span><span>8 C 1 2
</span>To find for C, you can use the equation:
(2000+100+10C+8) x 4 = 8000+100C+10+240C = 432-12 = 420
Therefore,
C = 7
So, the number is 2178.
<span>arc length = circumference • [central angle (degrees) ÷ 360]
Solving this equation for circumference:
</span>
<span>circumference = arc length / (central angle / 360)
</span><span>circumference = 12 / (85/360)
</span>circumference = 12 / <span><span>0.2361111111
</span>
</span>
<span>circumference =
</span>
<span>
<span>
<span>
50.8235294118
</span>
</span>
</span>
Source:
http://www.1728.org/radians.htm
I dont understand you already answered
