In the product
$\overrightarrow{\mathrm{F}}=\mathrm{q}(\overrightarrow{\mathrm{v}}\times \overrightarrow{\mathrm{B}})=\mathrm{q}\overrightarrow{\mathrm{v}}\times \left(\mathrm{B}\widehat{\mathrm{i}}+\mathrm{B}\widehat{\mathrm{j}}+{\mathrm{B}}_0\hat{\mathrm{k}}\right)$
For q = 1 and $\overrightarrow{\mathrm{v}}=2\widehat{\mathrm{i}}+4\widehat{\mathrm{j}}+6\widehat{\mathrm{k}}\text{ and }\overrightarrow{\mathrm{F}}=4\widehat{\mathrm{i}}-20\widehat{\mathrm{j}}+12\hat{\mathrm{k}}$
What will be the complete expression for $\overrightarrow{\mathrm{B}}$ ?