Q. If $\overrightarrow{a}, \overrightarrow{b}$ and $\overrightarrow{a}$ are unit vectors satisfying $| \overrightarrow{a}- \overrightarrow{b} |^2+| \overrightarrow{b}-\overrightarrow{c} |^2+| \overrightarrow{c}-\overrightarrow{a} |^2=9, $ then $| 2\overrightarrow{a}+5 \overrightarrow{b}+5\overrightarrow{c} |$ is equal to
IIT JEEIIT JEE 2012Vector Algebra
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