MathematicsMedium202×since 2002Q5780Let a⃗=2i^−7j^+5k^,b⃗=i^+k^\vec{a}=2 \hat{i}-7 \hat{j}+5 \hat{k}, \vec{b}=\hat{i}+\hat{k}a=2i^−7j^+5k^,b=i^+k^ and c⃗=i^+2j^−3k^\vec{c}=\hat{i}+2 \hat{j}-3 \hat{k}c=i^+2j^−3k^ be three given vectors. If r→\overrightarrow{\mathrm{r}}r is a vector such that r⃗×a⃗=c⃗×a⃗\vec{r} \times \vec{a}=\vec{c} \times \vec{a}r×a=c×a and r⃗⋅b⃗=0\vec{r} \cdot \vec{b}=0r⋅b=0, then ∣r⃗∣|\vec{r}|∣r∣ is equal to :A117\frac{11}{7}711B1152\frac{11}{5} \sqrt{2}5112C9147\frac{\sqrt{914}}{7}7914D1172\frac{11}{7} \sqrt{2}7112Check answerSkip