Summer Clouds
21/06/2017 at 08:56-
Let b,r,w be the number of blue bricks,red ones and white ones
\(\left(b,r,w\in Z^+;b+r+w=50;b< r< w;w=11b\right)\).We have :
\(\circledast b+r+w=50\Rightarrow b+w< 50\)
\(\circledast w>r\Rightarrow b+w>r\Rightarrow2\left(b+w\right)>r+b+w\Rightarrow b+w>25\)
\(\Rightarrow25< 12b< 50\Rightarrow2< b\le4\)
If b = 3,then w = 33 and r = 50 - 3 - 33 = 14 (satisfy)
If b = 4,then w = 44 and r = 50 - 4 - 44 = 2 (absurd)
Hence,(b,r,w) = (3 ; 14 ; 33) and w - r = 19
So,the answer is C
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The answer is C: 19
There are: 33 bricks of white, 3 bricks of blue (33:11=3), 14 bricks of red (50-33-3=14)
There are: 33-14=19 fewer red bricks than white ones.